<Product Info>
 This is an integrated editor, C subset interpreter,
 and scientific graphics program.

 THIS PROGRAM WAS WRITTEN BY THOMAS W. STEINER
 COPYRIGHT 1992 - 1996, ALL RIGHTS RESERVED
 THERE IS NO WARRANTY OF ANY KIND. USE AT YOUR OWN RISK.
 THIS IS NOT FREEWARE. TO REGISTER YOUR COPY SEND $50 TO

	   T.W. Steiner
	  2246 E. 6th Ave.
     Vancouver, BC, V5N - 1R1
	      Canada
       e-mail steiner@sfu.ca or
       tsteiner@creo.bc.ca

 Registered users will be able to download
 upgrades as they become available.

<Help>
 Select each menu item in the help menu to get an
 overview of the program capabilities. Some important
 user interface details that go beyond the standard
 are also discussed in the menu help item.

<Cursor Motion>
 The cursor may be moved around with the following keys:
 #4 -- left one space
 #6 -- right one space
 #8 -- up one line
 #2 -- down one line
 #1 -- end of line
 #7 -- beginning of line
 #3 -- scroll down one screen
 #9 -- scroll up one screen
 #T -- left one word
 #V -- right one word
 #X -- up five lines
 #R -- down five lines
 #Q -- end of file
 #W -- beginning of file
 #S -- end of file
 #Y -- beginning of file
 #q -- end of page
 #w -- top of page
 #s -- down half a page
 #y -- up half a page

<Mouse>
 The mouse may be used to position the cursor as an
 alternative to using the keyboard. Click on the
 desired text location. The text may be scrolled using
 the scroll bars at the sides.

 All three mouse buttons are used to mark regions of
 text by draging. The marking mode button assignments
 are made in the editor configuration menu.

 Double clicking on a word in a regular file causes
 the editor to search for this word in an *.ndx file
 and if found there starts up the info viewer. This is
 useful in conjuction with function reference material
 from compiler vendors. The path to *.ndx files is
 specified in the editor configuration menu. Once set
 up this enables context sensitive help on any
 recognized word in the text.

 Double clicking on a word in a readonly file causes
 the editor to interpret that word as a file name and
 loads that file. Integer numbers after the name if
 any are interpreted as the line and column numbers
 respectively. This is very convenient with the output
 from a compiler invoked from the command line since
 the output is added to the editor ring as a read only
 file.

<Menus>
 The menus function in a somewhat non-standard way.

 The standard ALT f file menu access has not been
 implemented since these keys are used for direct
 accelerators. However key board menu access is still
 possible by using the ALT key by itself if this is
 enabled in the editor configuration.

 To get help on any menu item click on it using the
 right rather than the left mouse button.

 Almost every menu item has an associated accelerator
 which may be mapped to any other key or keys. Note
 that if the keys are remapped this mapping will
 appear in the menus after restarting the editor.

 Since there are so many accelerator key definitions
 the accelerators are case sensitive so look
 carefully.

<Quit>
 Exits from the currently displayed file. The next
 file in the ring is displayed provided one exits. If
 no other files are loaded the editor itself quits.
 The number of loaded files is reported in the title
 bar along with the current file name. If the file has
 been modified a confirm dialog will be shown. To exit
 from all the files and terminate the editor use the
 "close" (or Alt F4) from the system menu.

 The default accelerator is Ctrl q mapped to ^Q

<Save>
 The editor writes the currently displayed file to
 disk using the current name and path. If a newer file
 of the same name exist then a confirm dialog will be
 displayed.

 The default accelerator is Ctrl w mapped to ^W

<Save As...>
 The editor saves the currently displayed file to disk
 using the specified name and path. A standard file
 dialog is opened so that a filename can be typed or
 chosen.

 The default accelerator is Ctrl W mapped to ^w

<Save All Changed>
 All files loaded that have had changes made to them
 are saved to disk.

 The default accelerator is Ctrl A mapped to ^a

<Open...>
 A standard file dialog is displayed which allows
 selection of a file to be edited. A wildcard '*' in
 the name will load all matching files. Files may also
 be loaded from the command line by typing
 '^[ e yourfile.name'.

 The default accelerator is Ctrl O mapped to ^o

<Next>
 The next file in the ring of loaded files is displayed.

 The default accelerator is Ctrl n mapped to ^N

<Prev>
 The previous file in the ring of loaded files is
 displayed.


 The default accelerator is Ctrl p mapped to ^P

<Other...>
 Opens a listbox dialog which displays a list of all
 the files currently loaded. A file to be displayed
 may be selected by double clicking on the chosen
 filename. Changed files have the word changed
 appended to the file name.

 The default accelerator is Ctrl H mapped to ^h

<Config...>
 Opens the editor configuration notebook. Many editor
 preferences such as the colours may be set. The
 results are saved in the ASCII file editor.cfg so
 that the next time the editor starts it will use the
 selected configuration. If multiple editor instances
 are started only the first one will write the
 editor.cfg file.

 The default accelerator is Ctrl C  mapped to ^c

<Cmd...>
 Opens a command line dialog. Commands to the
 operating system as well as editor command line
 commands may be entered. The listbox displays a
 history of the recently used command line commands
 for reuse by double clicking on them. Command line
 commands may also be entered without opening this
 dialog by hitting the ^[ key. The editor command line
 commands are as follows:

 The default accelerator is Ctrl M  mapped to ^m

 Command Line Operations

 ^[                    goto or leave command line

 Change current line.
    number                goto line number n
   +number                down n lines
   -number                up n lines

 Change current column offset.
   @number                start at column n
   @+number               scroll left n columns
   @-number               scroll right n columns

 Search and Replace.
   /str1[/-bclrw]
      find string str (/ may instead be other punct)
   c/str1/str2[/-bclrw]      replace str1 with str2

   The optional search suffixes are
      /-        search up (down is the default)
      /b        search marked block only
      /c        ignore case
      /l        loop through all loaded files
      /r        interpret as regular expression
      /w        match whole words only

   For regular expressions the following symbols have
   special meaning:
      ^ start of line
      \$ end of line
      . any character
      \\ literal next character
      + match one or more times
      * match zero or more times
      [aei0-9]   match a,e,i and 0 through 9
      [^aei0-9]  match anything but a,e,i and 0 through 9
      (  )       sub expression
      a(ab)*b    matches ab aabb aababb aabababb etc.

 loading additional files to edit
   e name1,name2,...[-brfl]
   edit name1,name2,...[-brfl]

   The optional edit suffixes are
     -b        binary mode
     -r        read only
     -f num    first line is line number num (-r implied)
     -l num    last line is line number num (-r implied)

 cfg or configure      show and modify editor config

 help or ?             activates help

 quit                  exit without saving changes

 m [name] or           insert named file at cur location
 merge [name]

 r [name]  or          rename current file to name
 rename [name]

 d [name]  or          diff between current and named file
 diff [name]           diff between current and named file

 up arrow              previous command line entered
 down arrow            next command line entered

 fill [string]         fill B marked block with string

 sort [col]            sort lines using field col as key

 hex [num] or hex 'c'  convert decimal num or char to hex

 dec [num] or dec 'c'  convert hex num or char to decimal

 asc [num]             convert hex or dec number to char

 cd [y:\path]          set default drive and path

 os [command]          send command to operating system
 [command]             sent to operating system

 The results of the above operating system calls will
 end up in a temp file in the ring of files. There is
 a difference between the above two methods. When a
 command is prefixed by "os" the command runs
 synchronously i.e. the editor is blocked until the os
 command completes. If the "os" prefix is absent the
 system call runs in back ground. This is useful for
 compiling code or doing long searches in background
 for example.

 Lastly, any string that is sent to the operating system
 will first have any occurances of \$EDNAME translated to
 the current filename. In this way a generic macro that
 does an os call may be built.

<Delete Character>
 Deletes the character under the cursor.

 The default accelerator is Ctrl d mapped to ^D

<Delete Prev Char>
 Deletes the character to the left of the cursor. If
 the cursor is at the start of a line it will join the
 current line to the previous line.

 The default accelerator is Backspace mapped to ^H

<Delete Word>
 Deletes all characters under and to the right of the
 cursor up to the next space or punctuation.

 The default accelerator is Ctrl z mapped to ^Z

<Delete to Line end>
 Deletes all characters under and to the right of the
 cursor up to the end of the line.

 The default accelerator is Ctrl e mapped to ^E

<Delete Line>
 Deletes the entire current line.

 The default accelerator is Ctrl Back mapped to ^?

<Insert New Line>
 The behaviour of this command is dependent on the
 'conventional return' configuration setting. If
 conventional return is on then the current line is
 split at the cursor and the remainder is put on the
 next line. If however, conventional return is not
 enabled then this command inserts a blank line below
 the current line leaving the current line intact.
 This behaviour is compatible with the 'e' series of
 editors.

 The default accelerator is Enter mapped to ^M

<Change Char Case>
 Changes the case of the character under the cursor.

 The default accelerator is Ctrl c mapped to ^C

<Swap two Chars>
 Swaps the character under the cursor with the one
 to the right of the cursor.

 The default accelerator is Ctrl s mapped to ^S

<Insert Ctrl Char>
 This command starts a dialog for entering the 3 digit
 ASCII code of a character to be inserted in the text. 
 This is useful for inputing characters without a key
 board key. 

 The default accelerator is Alt x mapped to %X

<Insert Literal Char>
 This is only active if key mapping is turned on in
 the editor configuration menu. If it is turned on
 then this command will for the next key stroke
 disable the translation so that the original
 functionality may be accessed.

 The default accelerator is Alt k mapped to %K

<Cut Line at Cursor>
 This command splits the current line at the cursor
 puting the remainder of current line on the next
 line. Similar to Insert New Line if conventional
 return is enabled. Used to split lines if
 conventional return is not enabled.

 The default accelerator is Ctrl k mapped to ^K

<Join two Lines>
 This command joins the next line to the end of the
 current line.

 The default accelerator is Ctrl j mapped to ^J

<Left justify line>
 This command adjusts the indentation of the current
 line to match that of the next non blank line above.
 If a block of lines was just copied or moved this key
 will adjust the indentation of the whole block.

 The default accelerator is Alt j mapped to %J

<Toggle Ins/Del>
 This command toggles the character insertion mode
 between insertion and replacement. The current status
 is reported on the right end of the status line.

 The default accelerator is Ctrl t mapped to ^T

<Undo>
 The last changes to a line or block of lines are
 restored. The number of undo levels are essentially
 unlimited but can be otionally disabled in the editor
 configuration menu.

 The default accelerator is Ctrl u mapped to ^U

<Redo>
 Steps undone with the undo command can be redone with
 this command.

 The default accelerator is Ctrl r mapped to ^R

<Restore Current Line>
 If the undo record for the current line is of the
 line change type then the line can be restored to its
 previous state using this command. The difference
 between this command and undo is that this command
 can restore a line in some cases without having to
 undo changes made after the current line was
 modified.

 The default accelerator is Alt q mapped to %Q

<Reflow>
 This command has two different modes of operation. If
 syntax colouring is not on then this command
 reformats a paragraph of text using the margins and
 indentation specified in the editor configuration
 notebook. The reformating starts at the current line
 and ends at the first blank line. Alternatively a
 block mark may be set to specify the margins and text
 to reflow.

 If syntax colouring is on then it is assumed that the
 text is C code and it is reformated with smart
 indentation At this point the rules are not
 configurable and may not suit everyone's taste.

 The default accelerator is Alt r mapped to %R

<First Column Lines>
 This command folds up the current file so that only
 those lines starting in the first column are visible.
 This is useful for rapidly locating functions in a
 file. If the file is already folded then this command
 unfolds the file around the line current line.

 The default accelerator is Ctrl v mapped to ^V

<Lines with search string>
 This command folds up the current file so that only
 those lines containing the last used search string
 are visible. If the file is already folded then this
 command unfolds the file around the line current
 line.

 The default accelerator is Alt s mapped to %S

<Changed Lines>
 This command folds up the current file so that only
 those lines which have been modified since the last
 save are visible. If the file is already folded then
 this command unfolds the file around the line current
 line.

 The default accelerator is Alt v mapped to %V

<Lines with placemark>
 This command folds up the current file so that only
 those lines which contain a placemark are visible. If
 the file is already folded then this command unfolds
 the file around the line current line.

 The default accelerator is Alt h mapped to %H

<Tagged foldup>
 This command folds up the current file so that the
 lines between the numerically greatest remaining fold
 tag and the next fold tag are hidden. The fold tag is
 a regular expression set in the editor configuration
 dialog and should be picked to be a comment in the
 language in use. For example the default regular
 fold tag expression is //[ ]*L[0-9]+ which is a comment
 in C++. This will match // L1 and // L21 for example.
 The number represents the fold level.

 Tagged foldup is the only folding mode that requires
 special entries in the file. However, a file written
 with folding in mind can make use of these tags to
 selectively hide details to present an overview.

 The default accelerator is Alt - mapped to %-

<Tagged unfold>
 Unfolds previously folded text by one level if folded
 by tagged foldup. If folded in another mode the file
 is completely unfolded. The file is unfolded around the
 current line.

 The default accelerator is Alt + mapped to %+

<Tabbed foldup>
 This command folds up the current file so that the
 most indented text which remains visible is hidden.
 This provides a means of hidding the details of a
 large switch() for example to get an overview.

 The default accelerator is Ctrl - mapped to ^-

<Tabbed unfold>
 Unfolds previously folded text by one level if folded
 by tabbed foldup. If folded in another mode the file
 is completely unfolded. The file is unfolded around the
 current line.

 The default accelerator is Ctrl + mapped to ^+

<Split Screen>
 The screen is split into an upper and lower half each
 of which can show the same or a different file. If the
 screen is already split then it is unsplit.

 The default accelerator is Ctrl y mapped to ^Y

<Other Split Half>
 This command is only active if the screen is split in
 which case it moves the cursor to the other split half.
 It is also possible to click with the mouse to select
 the other half.

 The default accelerator is Ctrl o mapped to ^O.

<Alternate Binary Rep>
 If the file being edited is a binary file then this command
 switches from the hex representation to a text and control
 key representation.

 The default accelerator is Alt a mapped to %A.

<Normal Mark>
 This is the industry standard mode of text marking which
 is of more use with standard text than with program code.
 Use this command to mark the start and end of a region.
 A region may start in the middle of a line extend over
 several lines and end in the middle of a line.

 The default accelerator is Alt n mapped to %N.

<Unmark>
 Unmark any text marked in any one of the three marking
 modes.

 The default accelerator is Alt u mapped to %U.

<Delete region>
 This deletes a region marked in any one of the three
 marking modes.

 The default accelerator is Alt d mapped to %D.

<Move region>
 This moves a region marked in any one of the three
 marking modes to the location in the same or different
 file specified by the current cursor location.

 The default accelerator is Alt m mapped to %M.

<Copy region>
 This copies a region marked in any one of the three
 marking modes to the location in the same or different
 file specified by the current cursor location.

 The default accelerator is Alt c mapped to %C.

<Yank back last del>
 The last region deleted can be restored once or many
 times using this command. The last deleted text is
 inserted at the current cursor location in the same
 or different file. Note that the text may be brought
 back in any location so that this provides a means
 of moving text in a method conceptually similar to
 using a clip board.

 The default accelerator is Alt y mapped to %Y.

<Write region>
 The currently marked region is written to a temp
 disk file with name 'editblck.tmp' in the current
 directory.

 The default accelerator is Alt w mapped to %W.

<Mark lines(s)>
 This is the prefered marking mode for program
 text. Only whole lines are marked and line marked
 text when inserted on a copy does not split the
 current line as in normal marked case but inserts
 the marked lines below the current line.

 The default accelerator is Alt l mapped to %L.

<Justify>
 This command left adjusts the current line with the
 first non-blank line above and then moves the cursor
 down to the next line. As a special case if the last
 operation was a marked region move or copy then the
 whole block is shifted left or right as necessary
 to left adjust the first line.

 The default accelerator is Alt j mapped to %J.

<Mark Rect Block>
 This command is used to mark a rectangular block
 for column manipulations.

 The default accelerator is Alt b mapped to %B.

<Fill Rect>
 A previously marked rectangle may be filled with
 a single character. To fill with a word use the
 command line command 'fill xyz'. Alternatively,
 this command may be used to change the case of
 all the characters in the marked block. Lastly,
 this command may be used to fill with a sequence
 of incrementing or decrementing numbers starting
 with the number found at the top of the block
 marked region region.

 The default accelerator is Alt f mapped to %F.

<Overlay Block>
 The block marked region is used to overwrite a
 same sized region the top left corner of which
 is specified by the current cursor location.

 The default accelerator is Alt o mapped to %O.

<Move Rect Left>
 A block marked region may be moved to the left
 by one space with this command. The contents of
 the column to the left of the block is deleted.
 The text to the right of the marked block moves
 with the text. This command is useful for adjusting
 the indentation of a section.

 The default accelerator is Alt Left mapped to #t.

<Move Rect Right>
 A block marked region may be moved to the right
 by one space with this command. The text to the
 right of the marked block moves with the text.
 This command is useful for adjusting the indentation
 of a section.

 The default accelerator is Alt Right mapped to #v.
 A block marked region may be shifted to the left
 by one space with this command. The contents of
 the left most column of the block is deleted and
 the width of the block shrunk by one
 The text to the right of the marked block moves
 with the text. This command is useful for adjusting
 the indentation of a section.

 The default accelerator is Alt Left mapped to #t.

<Move Rect Up>
 A block marked region may be moved up by one line
 with this command. The contents of the line above
 the block is split to accomodate the block.

 The default accelerator is Alt Up mapped to #x.

<Move Rect Down>
 A block marked region may be moved down by one line
 with this command. The contents of the line below
 the block is split to accomodate the block.

 The default accelerator is Alt Down mapped to #x.

<Shift Rect Left>
 A block marked region may be shifted to the left
 by one space with this command. The left most column
 of the block is deleted and the marked region's width
 is reduced by one provided the width of the column is
 wider than one. If not the block width stays at one and
 a new column is shifted in from the right. Text to the
 right of the marked block shift with the text in the
 block. This command is useful for adjusting
 the indentation of a section.

 The default accelerator is Ctrl ^ mapped to ^^.

<Shift Rect Right>
 The text in  block marked region may be shifted to the
 right by one space with this command. The right most
 column of the block is filled with spaces Text to the
 right of the marked block shift with the text in the
 block. This command is useful for adjusting
 the indentation of a section.

 The default accelerator is Ctrl _ mapped to ^_.

<Copy to Clipboard>
 This command copies a region marked in any one of the
 three marking modes to the system clip board.

 The default accelerator is Ctrl ins mapped to #P.

<Copy From Clipbrd>
 This inserts lines of text from the system clipboard
 below the current line.

 The default accelerator is Shift Ins mapped to #a.

<Copy to Clip and Del>
 This command copies and deleted a region marked in any
 one of the three marking modes to the system clip board.

 The default accelerator is Shift Del mapped to #d.

<Toggle Placemark>
 This command sets a placemark on the current line if
 there is not already a placemark otherwise it removes
 the place mark.

 The default accelerator is Ctrl a mapped to ^A.

<Goto Last Place>
 This command moves the cursor to the next location
 marked by a previously set placemark.

 The default accelerator is Ctrl l mapped to ^L.

<Clear Placemarks>
 This command clears all previously set placemearks.

 The default accelerator is Alt i mapped to %I.

<Goto Last Pos>
 This command returns the cursor to the line it was on
 previously. This command is useful in case the cursor
 was accidentally removed from the region of interest
 with an uninteded search for example.

 The default accelerator is Alt p mapped to %P.

<Match Bracket>
 This command moves the cursor to the location matching
 the bracket or comment start underneath the cursor.
 Note that the cursor must currently be positoned on a
 bracket or comment delimiter.

 The default accelerator is Ctrl b mapped to ^B.

<Goto Line num>
 This command opens a dialog for entering the line number
 of the desired current line. There is also a command
 line equivalent which is:

 ^[ nnn Enter

<Teach Macro (start,end)>
 This command starts or ends the recording of keystrokes
 for a macro. At the end of macro recording it may be
 optionally bound to a function key for preservation
 between editing sessions. Otherwise it will be stored
 for re-execution with the Exec Last Macro command until
 the end of the current editing session unless over
 written by another recorded macro.

 Macros can be used together with command multiplication
 to carry out repetitive complex editing tasks.

 The default accelerator is Alt t mapped to %T.

<Exec Last Macro>
 This command executes the last recorded macro. Bound
 macros are executed by hitting the corresponding
 function key.

 The default accelerator is Alt e mapped to %E.

<Zero Cmnd Mult>
 This command is used re set a previously entered
 command multiplier to zero,

 The default accelerator is Alt z mapped to %Z.

<Cmnd Multiplier>
 This command opens a dialog to enter a command multiplier.
 Command multiplication is very useful in conjuction with
 recorded macros for executing complex repetitive editing
 tasks. The default accelerators are:

 Alt 0 to Alt 9 mapped to %0 to %9.

<Find...>
 This command opens the search dialog used to enter the
 search string and search options. Search options are:

     search up (down is the default)
     search marked block only
     ignore case
     loop through all loaded files
     interpret as regular expression
     match whole words only

 For regular expressions the following symbols have
 special meaning:

      ^ start of line
      \$ end of line
      . any character
      \\ literal next character
      + match one or more times
      * match zero or more times
      [aei0-9]   match a,e,i and 0 through 9
      [^aei0-9]  match anything but a,e,i and 0 through 9
      (  )       sub expression
      a(ab)*b    matches ab aabb aababb aabababb etc.

 The default accelerator is CTRL S mapped to ^s.

<Replace...>
 This command opens the search and replace dialog used to
 enter the search and replace strings as well as the
 search options. Search options are:

     search up (down is the default)
     search marked block only
     ignore case
     loop through all loaded files
     interpret as regular expression
     match whole words only

 For regular expressions the following symbols have
 special meaning:

      ^ start of line
      \$ end of line
      . any character
      \\ literal next character
      + match one or more times
      * match zero or more times
      [aei0-9]   match a,e,i and 0 through 9
      [^aei0-9]  match anything but a,e,i and 0 through 9
      (  )       sub expression
      a(ab)*b    matches ab aabb aababb aabababb etc.

 The default accelerator is CTRL R mapped to ^r.

<Find Next>
 This command uses the last set search string and option
 to find the next match.

 The default accelerator is CTRL f mapped to ^F.

<Change Dir & Find>
 This command uses the last set search string and option
 to find the next match after toggling the current
 search direction

 The default accelerator is CTRL F mapped to ^f.

<Find Next cur word>
 This command uses the word under the cursor as the
 temporary search string and finds the next such match.

 The default accelerator is Alt * mapped to %*.

<Find Prev cur word>
 This command uses the word under the cursor as the
 temporary search string and finds the previous such
 match.

 The default accelerator is Alt / mapped to %/.


<general>
    To plot a figure load a .spt file.
 For example:

 <esc> edit demo\logaxes.spt or use the 'Open'
 button in the 'File' menu.

 then hit CTRL G or 'Execute' button.

    The next section explains how to use the mouse. For
 help with the editor select help in the editor window.

 Using The Mouse

    Double clicking the left mouse button with the mouse on
 the drawing page inserts the current x,y coordinates into
 the text file at the current text cursor location. If the
 mouse cursor is in the text region then hitting the left 
 mouse button will move the current text cursor to the mouse 
 cursor location. The left mouse button is also used to 
 select items in drop down menus. A rubber band box is drawn
 by pressing the left mouse button with the mouse over the 
 plot window and dragging the mouse with the left button held 
 down. The second point of the box is set to the location at
 which the button is released. Double clicking the left mouse 
 button in the text window results in an action depending on
 the type of file and type of word under the mouse cursor. 
 If the word under the cursor is a variable the value of the 
 variable or constant is displayed. If the word is a 
 function then the help screen for that function will be 
 loaded. If the current file has a read only attribute then 
 the editor attempts to interpret the word under the cursor 
 as a file name and subsequently load in that file.

    The right mouse button is used for highlighting 
 elements of a drawing. If the mouse cursor is on top of a 
 displayed element on the drawing page and the right mouse
 button is hit then the corresponding element is highlighted 
 in intense white and the text cursor jumps to the 
 corresponding line in the text that generated that element. 
 Conversely, if the mouse cursor is on the text side hitting
 the right mouse button will highlight any graphics elements 
 generated by the line under the mouse cursor. This feature 
 is very useful for finding the code associated with a
 particular element of a drawing or the reverse. Clicking the 
 right mouse button on a drop down menu item will open a
 help window for that item if available. 

    When the mouse cursor is on the drawing page the
 current coordinates are printed at the bottom. The units 
 and origin used are those in effect at the end of the last
 program execution. The default units are cm with the origin 
 in the bottom left corner of the page. Pressing the middle 
 mouse button (or both the left and right mouse buttons 
 together on two button mice) with the mouse pointer on the 
 drawing page causes the current coordinate reference point 
 to be reset so that the current coordinate line
 subsequently reports the distance from this point. 

 In the editor window the mouse can also be used to mark a
 region. Three types of regions are available and can be
 assigned to any one of three mouse buttons as set up in the
 "config" notebook of the "file" menu. 



    Actions associated with the menu buttons 

    There are several menu buttons along the top of the 
 display. The action of these buttons is as follows. 
 Starting at the left top there are four buttons labelled 
 'Draw', 'Slib', 'Cnst', 'SetO' and 'Keyw'. These activate 
 drop down menus which allow a function to be selected and 
 inserted into the text. The 'Draw' functions are a suite of 
 drawing routines which cause lines, arcs, text etc. to be 
 drawn to the page. The 'SetO' menu is a list of textual
 names for numerical constants which are used in conjunction
 with the set(); command to change attributes of the current 
 graphics state such as the current colour, line width, line 
 style, axes type, etc. Choosing set from the list of 
 drawing functions automatically opens a menu with only an
 appropriate subset of these and is the recommended 
 approach. The 'Slib' button allows selection of a standard 
 C library function. Most of these are math functions such
 as sin() and will not be required for making ordinary 
 plots. They are however useful for manipulating data before 
 plotting or generating data mathematically all from within 
 Splot. The 'Cnst' button opens a menu containing all the 
 constants defined in splot.h. The last button of this group 
 'KeyW' opens a list of C keywords for selection. The only 
 one of these that is of interest for ordinary plots is 
 'main'. Every file that generates a plot or drawing must 
 start with 
 
#include splot.h
main
   {
   /* list of drawing commands go here */ 
   /*   between the braces on as many*/
   /* lines as necessary */
   }

    This is all automatically inserted in the text by 
 selecting 'main'. The remaining keywords in this list are
 only of interest when constructing loops or branches. 

    The next button labelled 'Misc' opens a sub menu 
 containing the options 'Reset', 'Redraw' , 'Coord Match' 
 and 'Relative Coord'. 'Reset' resets splot to its initial 
 state and erases the current drawing. The 'Redraw' button 
 can be useful if Splot is in the incremental draw mode in 
 order to fix up blemishes caused by out of order drawing ad 
 erasing. 'Redraw' just re draws the current plot. The button
 'Coord Match' toggles the current units from cm to units 
 matching those defined in the last axes_box() and back. The 
 button 'Relative Coord' toggles the coordinate display from 
 reporting the absolute coordinate to reporting the distance
 between the mouse position and the current point defined 
 using the middle mouse button or double clicking the left 
 mouse button over the plot window. 

    The next button along the top is concerned with
 displaying the drawing. The default size of the drawing is
 one which fits on a standard 8 x 11 inch piece of paper if
 printed. However, as the screen resolution is not as good
 as that of printers it is possible to zoom in on part of a
 drawing in order to get a better view. To zoom in on part
 of a drawing hold down the left button and drag the mouse
 to enclose the region of interest. Then select the zoom
 button and pick the drop down menu item 'Box Zoom'. The
 button 'Undo Zoom' restores the previous view. The buttons
 'Save View' and 'Rest View' allow interesting views to be
 saved on a stack and restored respectively.

<abs>
 int abs(int i);

 Returns the absolute value of i;
 
<acos>
 double acos(double x);
 
 Returns the arc cosine of the value x. x must be 
 between -1 and 1. Returns a value between 0 and pi.

<arraydim>
 int arraydim(void *array,int i);

 Returns the number of elements in the ith dimension
 of the array. Returns -1 if it is not an array or if
 i is greater than the number of dimensions of the array.
 Dimension counting starts at 0. The second parameter is
 optional and if omitted the function returns the
 dimensions of the array.
 This is not a standard C library function.

<arraydup>
 void *arraydup(void *array);

 Returns a pointer to a duplicate of the array.
 Memory is malloced for the new array and the values
 in the old array copied to the new one.
 This is not a standard C library function.

<asin>
 double asin(double x);

 Returns the arc sine of the value x. x must be between
 -1 and 1. Returns a value between -pi/2 and pi/2. 
 
<atan>
 double atan(double x);
 
 Returns the arc tangent of the value x. Returns a value 
 between -pi/2 and pi/2. 
 
<atan2>
 double atan2(double y,double x);
 
 Returns the arc tangent of the value y/x. Returns a value 
 between -pi and pi. 
 
<atoi>
 int atoi(char *str);
 
 Converts a string to an integer. The string must contain 
 only digits. 
 
<atof>
 double atof(char *str);
 
 Converts a string to a double. The string must contain only 
 digits and 'e', 'E', '.', '-' and '+' . 
 
<ceil>
 double ceil(double x);
 
 Rounds up x to nearest integer value. 
 
<cos>
 double cos(double x);

 Returns the cosine of x. x is specified in radians.

<ctime>
 char *ctime(int tim);

 Returns a pointer to an ASCII string containing the
 current date and time. The passed parameter should
 be the value returned by the time() function for
 the current time and date.

 example:

 puts(ctime(time()));

 
<exit>
 void exit(int status);
 
 Terminates the execution of the program. If the status is 0 
 then it will be considered a normal exit otherwise an error 
 induced exit. 
 
<exp>
 double exp(double x);
 
 Calculates the exponential function e^x. 
 
<fabs>
 double fabs(double x); 

 Returns the absolute value of x. It is like abs() but works 
 with floating point numbers rather than integers. 
 
<floor>
 double floor(double x);
 
 Rounds down x to the nearest integer. 
 
<fmod>
 double fmod(double x,double y);
 
 Returns the remainder of x/y. 
 
<free>
 void free(char *ptr);

 Frees the block of memory pointed to by ptr. The memory 
 must have been previously allocated using malloc().
 
<log>
 double log(double x);
 
 Returns the natural log of x. 
 
<log10>
 double log10(double x);
 
 Returns the log base 10 of x.
 
<malloc>
 char *malloc(int size);

 Allocates a block of memory of size bytes and returns a
 pointer to the block. malloc returns NULL if there is
 insufficient free memory.

<max>
 double max{double x,double y);

 Returns the larger of x or y. This is NOT a standard
 C library function.

<min>
 double min{double x,double y);

 Returns the smaller of x or y. This is NOT a standard
 C library function.

<pow>
 double pow(double x,double y);

 Calculates x to the power y.

<puts>
 int puts(char *str);
 
 This routine writes the string str to the output file and 
 starts a new line. 
 
<printf>
 int printf(char *format,...);
 
 Prints the formatted data to the output file. The format 
 string specifies the type and number of values to print.
 Some common examples include: 
 
 printf("i = %d",i); prints the 
 integer value i. 
 
 printf("x = %g",x); prints the 
 floating point value x. 
 
 printf("text = %s",str); prints the 
 string str. 
 
 Multiple values can be printed as in 
 printf("%d %d %g %s",i,j,x,str); 
 
 The format specifiers can also include field width 
 information and justification etc. Consult a standard C
 text for more details. 
 
<print>
 void print(v,...);

 Prints the value v which can be of any scalar type. i.e
 int, char, float, double or a pointer. This is not a
 function found in the standard C library.

<rand>
 int rand();

 Returns random number between 0 and
 0x7FFF. Reseed using srand();

<sin>
 double sin(double x);

 Returns the sine of x. x must be specified in radians.

<sqrt>
 double sqrt(double x);

 Calculates the square root of x. x must be a positive
 number.

<srand>
 void srand(int seed);

 Reseeds the random number generator.
 Implicitly started with a seed of 1.

<sizeof>
 int sizeof(t);

 Returns the number of bytes required to store the value of
 type t.

<sprintf>
 int sprintf(char str,char
     *format,...); 
 
 Prints the formatted data to the string str. The format 
 string specifies the type and number of values to print.
 Some common examples include: 
 
 printf("i = %d",i); prints the 
 integer value i. 
 
 printf("x = %g",x); prints the 
 floating point value x. 
 
 printf("text = %s",str); prints the 
 string str. 
 
 Multiple values can be printed as in 
 printf("%d %d %g %s",i,j,x,str); 
 
 The format specifiers can also include field width 
 information and justification etc. Consult a standard C
 text for more details. 
 
<strcat>
 void strcat(char *dest, char 
      *source); 
 
 Concatenates the string source to the string dest. 
 
<strcpy>
 void strcpy(char *dest, char
      *source);

 Copies the string source to the string dest.

<strcmp>
 int strcmp(char *s1, char *s2);

 Compares the string s1 to the string s2.
 Returns < 0 if s1 is lexically < s2
 returns   0 if s1 equals s2
 Returns > 0 if s1 is lexically > s2
 
<strlen>
 int strlen(char *str);

 Returns the length of the string str.

<tan>
 double tan(double x);

 Calculates the value of the tangent of x. x should be
 specified in radians.

<time>
 int time();

 Returns the number of seconds elapsed since 00:00:00
 GMT January 1, 1970. Similar to the standard C library
 function time() but does not take a parameter.
 Generally used in conjunction with ctime();

<abox>
 void abox(double xsi, double
       ysi, double xorig,
       double yorig);

 Adds an axes box to the current path. The box is drawn with
 a size of xsi by ysi and centered on the page. No internal
 coordinate system is set up. Use ascale() for this or use
 axes_box() to combine both functions. All the parameters
 are optional and if present, specify the box size and
 position of the axes origin relative to the page origin. For
 the last two parameters the special constants XCENTER and
 YCENTER can be used for the x or y position coordinate
 respectively and will cause the axes box to be centered on
 the page along that axis. Using both XCENTER and YCENTER is
 equivalent to the default behaviour with the last two
 parameters absent. If no parameters are specified a default
 size of 12 by 16 cm is used and the box centered on the page.
 abox() is implicitly stroked.
 
<alineto>
 void alineto(double len, double ang);

 Adds a line of length len at an angle of ang with respect
 to the previous line to the current path. Generates an
 error if there is no current point. If there is no
 previous line then a horizontal line ending at the
 current point is assumed. The angle is in degrees and is
 the angle between an imaginary extension to the previous
 line and the current line.

 
<arc>
 void arc(double xcen, double ycen, double rad, double 
	   alpha, double beta); 
  
 Adds a circular arc of radius rad centered at (xcen, ycen) 
 to the current path. The starting angle is alpha and the 
 stopping angle is beta. The arc is drawn in the counter 
 clockwise direction. A straight line section will be added 
 from the previous current point if any to the starting 
 point of the arc. 
  
<arcn>
 void arcn(double xcen, double ycen, double rad, double 
	   alpha, double beta); 
  
 Adds a circular arc of radius rad centered at (xcen, ycen) 
 to the current path. The starting angle is alpha and the 
 stopping angle is beta. The arc is drawn in the clockwise 
 direction. A straight line section will be added from the 
 previous current point if any to the starting point of the 
 arc. Exactly as arc() but draws the arc in the opposite 
 direction. 
  
<arcto>
 void arcto(double x1, double y1, double x2, double y2, 
	    double rad); 
  
 Adds a circular arc of radius rad to the current path. The 
 center and angles are chosen so that the arc is tangent to 
 the line formed by (x1,y1) and the current point at its 
 start and tangent to the line (x1,y1) - (x2,y2) at its end 
 point. A straight line segment is added from the current 
 point to the start of the arc. An error is generated is 
 there is no current point. 
  
<arrowto> 
 void arrowto(double x,double y,...); 
  
 Adds a line segment to the current path from the current 
 point to (x,y). The line is terminated by drawing an arrow 
 head oriented in the direction of the line. More than one 
 coordinate point can be specified in the command in which 
 case a series of line segments terminated by arrows 
 connecting the points will be added to the current path. If 
 there is no current point then an error will be generated. 
 The size of the arrow head may be changed with the 
 set(FONTWIDTH,...); command.
  
<ascale>
 void ascale(int axes, double xstart, double ystart, double 
      xend, double yend); 

  or

 void ascale(int axes, double *data, int col,...); 

 An internal coordinate system is set up for subsequent 
 plotting of data within the existing axes box. The x axis 
 start and stop values are xstart and xend respectively and 
 ystart, yend for the y axis. for the y axis. If the axis 
 choice is XAXES or YAXES rather than XYAXES then only two 
 numbers follow the axes specifier rather than four. This 
 allows the x and y axes scales to be set independently of 
 each other. The alternate format allows for auto scaling to 
 the specified data. There can be more than one data array 
 in the list in which case the scales are chosen so that 
 they will all fit. Each data array can optionally be 
 followed by one or two integers specifying which columns to 
 use for the x and y values. If axes is not XYAXES only one 
 integer is allowed. 
  
<axes_box>
 void axes_box(double xsi, double ysi, double xstart, double 
       ystart, double xend, double yend,double xorig, double 
       yorig); 
  
 Adds an axes box to the current path. The box is drawn with 
 a size of xsi by ysi and centered on the page. An internal 
 coordinate system is set up for subsequent plotting of data 
 within the box. The x axis start and stop values are xstart 
 and xend respectively and ystart, yend for the y axis. for 
 the y axis. The last two parameters are optional and if 
 present specify the position of the axes origin relative to 
 the page origin. For the last two parameters the special 
 constants XCENTER and YCENTER can be used for the x or y 
 position coordinate respectively and will cause the axes 
 box to be centered on the page along that axis. Using both 
 XCENTER and YCENTER is equivalent to the default behaviour 
 with the last two parameters absent. More flexibility is 
 provided by the pair of functions abox() and ascale() which 
 provide the functionality of axes_box() in several steps. 
 axes_box() is implicitly stroked.
  
<box>
 void box(double x1, double y1, double x2, double y2); 
  
 Adds a box to the current path. The two end points of the 
 box are (x1,y1) and (x2,y2); 
  
<clear>
 void clear();
  
 Clears the screen when the program is executed. Also  
 the list of drawable elements is deleted.
 This function should not be needed for ordinary plots. 
  
<clip>
 void clip()
  
 Converts the currently defined path into a clipping path. 
 All subsequent drawing operations are then clipped against 
 this path and only portions of the drawing on the inside of 
 the clip path are displayed. What is inside and what is 
 outside depends on whether even-odd or non-zero wind has 
 been selected as the fill rule using a set(); If the 
 current path is not closed then the current path is first 
 closed. If there is no current path an error is generated. 
 Clip() is implicitly stroked and takes effect immediately.
  
<closepath>
 void closepath(); 
  
 Closes the current path. A straight line segment is added 
 from the current point to the start of the current path as 
 set by the moveto() of rmoveto() command at the beginning 
 of the path definition. Generates an error if there is no 
 current point. 

<cmatch>
 void cmatch(int on);

 If the passed parameter is TRUE then it does the necessary 
 translations and scaling so that the coordinate system for 
 the page matches that used within the axes_box. An error is 
 generated if there is no current axes_box. The font scale 
 is compensated automatically for the change in coordinate 
 system so that characters will still be the same size as 
 before. If the parameter is FALSE then the previous 
 unmatched coordinates will be restored. If there is no 
 parameter TRUE is assumed. 

<curveto>
 void curveto(double x1, double y1, double x2, double y2, 
	      double x3, double y3); 
 or
 void curveto(double *array,int first,int last);
 or
 void curveto(double *array);
  
 Adds Bezier curve sections to the current path starting 
 at the current point. The curve starts tangent to 
 (xcur,ycur) - (x1,x2) and ends tangential to (x2,y2) - 
 (x3,y3) at (x3,y3); An error is generated if there is no 
 current point. The number of coordinate points must be 
 a multiple of three else an error is generated.
 Several formats are allowed. The first is a list 
 of coordinate pairs. The second format is a pointer to a 2D 
 array of coordinate pairs followed by an optional pair of 
 integers specifying the first and last pairs to be plotted. 
  
<drawdata>
 void drawdata(double *data, int xcol, int ycol,...);

 Draws the data contained in the array data in the current
 axes_box. The numbers xcol and ycol are the columns of the
 array data that are to be used for the x-axis and y-axis
 data respectively. Each row of the array data represents
 one coordinate point to be plotted. The values will be
 plotted using the internal coordinate system established by
 the the call to axes_box. If there is no current axes box
 an error will be generated. The xcol and ycol params are
 optional. If no values are given then xcol = 0 and ycol = 1
 are assumed. For the popular case of one column of x values
 and a set of y values the whole set may be plotted using
 plotdata(data,xcol,ALL_Y);. drawdata() is implicitly stroked.
 More than one data set with corresponding xcol and ycol may
 be specified.

<errorbars>
 void errorbars(int axes,double *data, int xcol, int ycol, 
		int errcol); 

 Draws error bars for the data points in the array "data". 
 The first parameter is either XVALS or YVALS indicating 
 along which axes the error bars are to be drawn. The 
 numbers xcol and ycol are the columns of the array data 
 that are to be used for the x-axis and y-axis data 
 respectively. Each row of the array data represents one 
 coordinate point to be plotted. The values will be plotted 
 using the internal coordinate system established by the the 
 call to axes_box. The last parameter "errcol" is the column 
 of the array "data" which holds the size of the error for 
 the corresponding data point in the same row. If there is 
 no current axes box an error will be generated. 
 errorbars() is implicitly stroked.

<epsfile>
 void epsfile(char *filename);

 Writes the current graphics image to a file with the
 given name. The output format is encapsulated postscript.  
 Such a file can be printed on a postscript printer or 
 included as a graphic in many other programs. Warning! This
 command does not check if it is over writting an existing
 file.
  
<fill>
 void fill(); 
   
 Closes the current path if not already closed and fills the 
 interior region with the current colour as specified by the 
 last set() call. What is inside and what is outside the 
 path depends on the currently chosen fill rule. The fill 
 rule is either even-odd or non-zero wind (the default) and
 is specified using a set() call. An error is generated if
 there is no current path.

<fft>
 void fft(double *data, int rcol, int icol, char inv>

 Does a fast Fourier transform of the data. The last
 parameter is optional and if TRUE the inverse
 transform is done. The rcol parameter specifies the
 column of data which is the real part while icol is
 the column of data which is the imaginary part. To do
 a transform of a real function just arrange to have a
 column of zeros in your data. Note that the number of
 rows in the data set must be a multiple of 2. If not
 add rows to pad.

<fitline>
 void fitline(double *data, int xcol, 
  int ycol,double *yint,double *slope);

 Fits the best straight line to the data in the array "data" 
 using the column xcol of the array as the x values and the 
 column ycol as the corresponding y values. The best line is 
 drawn constrained to the current axes box. If there is no
 current axes box an error is generated. The last two 
 parameters are the returned values giving the y intercept 
 and slope of the fitted line. Note that they are pointers 
 to doubles which must be declared at the top of the 
 program. Given a declaration of the form: 
  
     double slope,yint;

 Call fitline using:

     fitline(data,0,1,&yint,&slope);

 Assuming that the first and second column of data are the x 
 and y values respectively. Data points can be excluded from 
 the fit by using the set(XRANGE,xmin,xmax); or 
 set(YRANGE,ymin,ymax); commands. Only data points within 
 the limits will be used for the fit. fitline() is 
 implicitly stroked.
  
<get>
 int or double get(int option, char *str); 

 Returns the value of the specified option in the current 
 graphics state. The numerical value for single valued 
 elements is returned by the function otherwise the return
 value is 0. A text representation of the value is optionally 
 returned in str. If used, be sure to allocate a character 
 array with sufficient space for str before calling this 
 function as in char str[80]; at the top of the program. The 
 valid option values are defined in splot.h. See also set() 
 for a description of the various options. The returned 
 string can be printed using the command puts(str); in the 
 program where "str" is the name of the array in the call to 
 get(). Returned numerical values can be printed using 
 print(value); The second array parameter is optional and is 
 only really needed for getting options that are more than 
 just a single value such as line patterns.

<grestore>
 void grestore(); 
  
 Pops a graphics state off the state stack thereby restoring 
 the graphics state that was in effect at the time the 
 matching gsave() was executed. In particular, the path, the 
 clip path, the line styles, line colours etc. are restored 
 to their previous values. 
  
<gsave>
 void gsave(); 

 Pushes the current graphics state onto the state stack. The 
 current path, clip path, line style, colour etc. are saved 
 so that they can be restored later using a grestore() 
 command. 
  
<label>
 void label(int axis, char *label); 

 Add labels to the axes box previously defined. The first
 parameter is which axis to label either BOTTOM, TOP, LEFT
 or RIGHT. The following parameter is the label to be
 printed. The label will be printed centered between the
 appropriate edges of the current axes box. An error is
 generated if there is no current axes box. All labels
 should be after plotdata() if used otherwise spacing from
 the axes may not be correct. The spacing can also be 
 changed using set(LABELMARG,...);. label() is implicitly 
 stroked. 

  
  
<lineto>
 void lineto(double x,double y,...); 
 or
 void lineto(double *array,int first,int last);
 or
 void lineto(double *array);
  
 Adds a line segment to the current path from the current 
 point to (x,y). More than one coordinate point can be 
 specified in the command in which case a series of line 
 segments connecting the points will be added to the current 
 path. If there is no current point then an error will be 
 generated. Several formats are allowed. The first is a list 
 of coordinate pairs. The second format is a pointer to a 2D 
 array of coordinate pairs followed by an optional pair of 
 integers specifying the first and last pairs to be plotted. 
  
<moveto>
 void moveto(double x, double y); 
  
 Sets the current point to (x,y). Also sets the path close 
 point to (x,y) for subsequent use with closepath(). Many 
 path building commands such as curveto() and lineto() require 
 that a current point exist before calling them. 
  
<newpath>
 void newpath(); 
  
 Resets the current path to NULL and also causes the current
 point to be undefined. Furthermore, it turns off the 
 implicit stroking of elements that are normally implicitly 
 stroked such as text();. Thus using newpath(); these 
 elements can be added to a path which must then be 
 explicitly stroked. stroke() turns on implicit stroking 
 again.
  
<plotdata>
 void plotdata(double *data, int xcol, int ycol,...);

 Plots the data found in array data in a box. This command
 chooses the scale sizes tick marks etc. to display the data
 which is assumed to be in order of monotonically increasing
 or decreasing x value order. The parameters xcol and ycol
 specify which columns of the array data to use for the x
 and y values respectively. The xcol and ycol params are
 optional. If no values are given then xcol = 0 and ycol = 1
 are assumed. For the popular case of one column of x values
 and a set of y values the whole set may be plotted using
 plotdata(data,xcol,ALL_Y);. If the default choices of
 plotdata are not acceptable a plot can be generated using
 the step by step method using axes_box(), tickmarks(),
 ticklabels() and drawdata(). The data must first be read in
 to array data using readdata(). plotdata() is implicitly
 stroked. More than one data, xcol, ycol triplet may be
 entered in which case the auto scaling ensures that the box
 is scaled to the max of all the data sets.
  
<rarrowto>
 void rarrowto(double x, double y,...); 
  
 Adds a line segment to the current path from the current 
 point to the current point plus x, y. The line is 
 terminated by drawing an arrow head oriented in the 
 direction of the line. This command is identical to arrowto 
 except that the displacement is specified relative to the 
 current point. More than one coordinate point can be 
 specified in the command in which case a series of line 
 segments terminated by arrows connecting the points will be 
 added to the current path. If there is no current point 
 then an error will be generated. The size of the arrow 
 head may be changed with the set(FONTWIDTH,...); command.

<readdata>
 void readdata(char * filename, double * data, int mod);

 Reads a file of name filename and puts the data into the
 array "data". The file should be in ASCII format with the x
 data in one column and the y data values next column(s).
 Any line containing non numeric characters or is blank will
 be considered a comment and ignored. WARNING! As an
 optimization data is only read from disk once if the
 configuration parameter always_load is off. Subsequent
 executions use the stored data already in memory (except
 after a reset). This means that if you modify the array
 "data" after reading in values the next time the file is
 executed you will get strange results. Similarly, if you
 reuse the same array for different plots in the same
 drawing you will have trouble. The motto is never change
 the values in the array "data". If you want to change the
 values declare another array and copy the values. Also
 remember that readdata() implicitly allocates memory for
 the data array so it is correct to declare the data array
 as double *data; at the top. If however, you are going to
 fill in a new array with calculated values you need to
 declare the array as double newdata[ysize][xsize]; so that
 space will be allocated. The last parameter is optional
 and if included and non-zero the data is read in as a
 single dimension array. Furthermore, x values are not
 generated if there is just a single column of numbers in
 the file. This modified form of readdata is useful for
 reading in numbers into an array to be used in lineto()
 etc.

<rcurveto>
 void rcurveto(double x1, double y1, double x2, double y2, 
	      double x3, double y3); 
 or
 void rcurveto(double *array,int first,int last);
 or
 void rcurveto(double *array);
  
 This is identical to curveto() except that the list of
 coordinates are all relative distances from previous point.
 Adds Bezier curve sections to the current path starting 
 at the current point. The curve starts tangent to 
 (xcur,ycur) - (x1,x2) and ends tangential to (x2,y2) - 
 (x3,y3) at (x3,y3); An error is generated if there is no 
 current point. The number of coordinate points must be 
 a multiple of three else an error is generated.
 Several formats are allowed. The first is a list 
 of coordinate pairs. The second format is a pointer to a 2D 
 array of coordinate pairs followed by an optional pair of 
 integers specifying the first and last pairs to be plotted. 
  
<reset>
 void reset(); 
  
 Restores all set able parameters to their default values. 
 Clears the current path and clip path. 
  
<rlineto>
 void rlineto(double x,double y,...); 
 or
 void rlineto(double *array,int first,int last);
 or
 void rlineto(double *array);
  
 Adds a line segment to the current path from the current 
 point to the current point plus x, y. This command is 
 identical to lineto except that the displacement is 
 specified relative to the current point. More than one 
 coordinate point can be specified in the command in which 
 case a series of line segments connecting the points will 
 be added to the current path. If there is no current point 
 then an error will be generated. Several formats 
 are allowed. The first is a list of coordinate pairs. The
 second format is a pointer to a 2D array of coordinate
 pairs followed by an optional pair of integers specifying 
 the first and last pairs to be plotted.
  
<rmoveto>
 void rmoveto(double x, double y); 
  
 Sets the current point to the current point plus x,y. This 
 command is the same as moveto except that a relative move 
 is specified. It also sets the path close point for 
 subsequent use with closepath(). Many path building 
 commands such as curveto and lineto require that a current 
 point exist before calling them. 
  
<rotate>
 void rotate(double ang); 
  
 Rotates the figure about the
 current origin by the the angle 
 specified. The angle units are
 degrees and the +ve direction
 is counterclockwise.  
 Changes in rotation are cumulative.

<rsplineto>
 void rsplineto(double x1,y1,x2,y2,...);
 or
 void rsplineto(double *array,int first,int last);
 or
 void rsplineto(double *array);

 This is identical to splineto() except that the list of
 coordinates are all relative distances from previous point.
 This function accepts a list of two or more coordinate 
 pairs and using the current point as the first point draws 
 a cubic spline which goes through all of the given 
 coordinates. It uses Bezier curves internally but 
 calculates the necessary control points in order to make 
 the derivative continous everywhere. An error is generated 
 if there is no current point. Specifying less than two 
 additional points also generates an error. Several formats 
 are allowed. The first is a list of coordinate pairs. The
 second format is a pointer to a 2D array of coordinate
 pairs followed by an optional pair of integers specifying 
 the first and last pairs to be plotted.
  
<scale>
 void scale(double xs, double ys); 
  
 Changes the scale of the figure
 by the factors specified for
 the x and y axes respectively.
 Changes in scale are cumulative.
  
<set>
 void set(int option, ...); 
  
 All set able parameters can be set using the set command. 
 The first parameter specifies which option to set. The 
 defined constants corresponding to valid options are 
 defined in the header file splot.h. What follows is a very 
 brief description of all the values set able using set(). 

 set(AXESCLIP,val);
 If val is ON then the data values are clipped to the limits 
 of the axes box. This is temporarily added to the user set 
 clip limits if any. If val is OFF (the default) then the 
 user specified clip limits from the last clip() call are 
 used. 
 Alternatively the range of data values plotted can be set
 using set(XRANGE,...); set(YRANGE,...); .

 set(AXESTYPE,val); 
 AXESTYPE may be one of the following. LINEAR (the default), 
 LOGX, LOGY, LOGLOG, INVX, INVY, INVINV, INVXLOGY or 
 LOGXINVY. The position of data points and tickmarks are 
 automatically adjusted to account for the axes type. 

 set(CURSYMBOL,sym);
 Sets the symbol to use when plotting data with symbols. sym 
 must be one of OCIRCLE,OSQUARE,OTRIANGLE,ODIAMOND 
 OSTAR,OARROW,PLUS,CROSS,MULT,CIRCLE,SQUARE,TRIANGLE, 
 DIAMOND,STAR,or ARROW. The default symbol is CIRCLE. The 
 size of a symbol can be changed using set(FONTWIDTH, 
 val_in_cm); since symbols are just a special font. 
 The size of a symbol can be changed using set(FONTWIDTH,
 val_in_cm); since symbols are just a special font. The 
 size relative to the current FONTWIDTH can be set using 
 set(SYMMULT,mult);. 

 set(FILLRULE,type);
 Determines the rule to be used when filling a path. Type 
 must be one of NONZWIND (default) or EVENODD. 

 set(FLATNESS,num);
 Sets the maximum allowable error in pixels when converting 
 a curve to a set of straight line segments. Smaller values 
 of num give smother curves but take longer to process. The 
 default value of num is 1.
  
 set(FONT,fonttype);
 Sets the font type to use for subsequent text written using 
 the text(); routine. fontname type be either SIMPLEX 
 (default) or COMPLEX. 
  
 set(FONTASPECT,asp);
 Sets the ratio of the glyph height to width used for text 
 written using text();. The default value is 2.0 
  
 set(FONTDIR,angle);
 Sets the rotation angle with respect to the x axis to use 
 when writing text using text(); The default is 0. 
  
 set(FONTMULT,factor);
 Multiplies the current font size by the given factor. 
  
 set(FONTWIDTH,wid);
 Sets the average width of the characters written using 
 text(). The default value is 0.7 cm. FONTWIDTH applies also 
 to symbols. 

 set(LABELMARG,val);
 Sets the additional margin between the axes box and the 
 labels. The default is 0.0 cm. 
  
 set(LINECAP,type);
 Determines how thick lines are to be terminated. The 
 allowed types are BUTTCAP (default), ROUNDCAP and PROJCAP. 
  
 set(LINECOLOUR,col); 
 Where col is one of INVIS, BLACK, BLUE, GREEN, CYAN, RED, 
 MAGENTA, BROWN or WHITE. This set the colour to use when 
 the current path is stroked or filled. The default colour 
 is BLACK with the background WHITE. 

 set(LINEJOIN,type);
 Determines how thick lines are joined together. The allowed 
 join types are MITERJOIN (default), BEVELJOIN and 
 ROUNDJOIN. 

 set(LINESTYLE,pattern,...);
 Sets the line style to use for the path when it is stroked. 
 The constant LINESTYLE is followed by a list of floating 
 point values that define the pattern. The values are 
 interpreted as the length along the path that the line is 
 visible followed by the length that it is invisible as an 
 alternating sequence wrapping back to the beginning when 
 the pattern reaches the end. For example a pattern of 
 1.0,1.0 implies on for 1 cm followed by off for 1 cm. A 
 pattern of 1.0,0.5 is on for 1 cm followed by off for 0.5 
 cm. The predefined patterns are: SOLID 0 (default) DASHED 
 1.0,0.5 DOTTED 0.2,0.2 and DOTDASH 1.0,0.5,0.2,0.5. There
 must always be an even number of comma separated values
 in a pattern definition.
  
 set(LINEWIDTH,width);
 Sets the line width to width cm (default 0.05 cm). This 
 line width is used when the current path is stroked. 
  
 set(MITERLIMIT,maxratio);
 Sets the maximum length of spikes formed by miter joining 
 two lines at an acute angle. If the ratio of the length of 
 the spike to the width exceeds the value of maxratio then a 
 BEVELJOIN is done instead. The default value is 10.0. 

 set(PAGEROT,flag);
 Selects landscape orientation if flag is ON. 
 Default is portrait.

 set(PATTOFF,offset);
 Sets the offset into the current LINESTYLE pattern. Can be
 used to adjust the starting point of a pattern for aesthetic
 reasons.
  
 set(PLOTTYPE,type);
 Sets the current plot type. type must be one of LINES 
 (default), SYMBOLS or SYM_LINES. LINES connects data points 
 with line segments while SYMBOLS causes the current symbol 
 to be drawn at each data point. SYM_LINES does both. 
 The size of a symbol can be changed using set(FONTWIDTH, 
 val_in_cm); since symbols are just a special font. The size 
 relative to the current FONTWIDTH can be set using 
 set(SYMMULT,mult);. 
  
 set(SCALEALL,val);
 If val is ON then the XSHIFT, YSHIFT, XMULT, YMULT values 
 are applied to all coordinates (i.e. in lineto, moveto etc.). 
 The default is OFF in which case only data plotted using 
 plotdata or drawdata is affected by these values. 


 set(SCRIPTSCALE,val);
 Sets the relative height of a super/sub script as compared 
 to ordinary text. The default value is 0.5. 

 set(SCRIPTSHIFT,val);
 Sets the distance that a super/sub script is shifted 
 above/below ordinary text. The value is specified as a 
 fraction of the ordinary text height. The default value is 
 0.7. 

 set(SYMMULT,val)
 Sets the symbol size multiplier used when drawing symbols. 
 The default value is 1.0. The actual symbol size is 
 determined the current FONTWIDTH multiplied by the curent 
 SYMMULT value.

 set(TICKLENGTH,len);
 Sets the length of axis tick marks to be used. The default 
 value is 0.3 cm. 

 set(TICKLMARG,len);
 Sets the margin between the axes box and the tick labels. 
 The default is 0.0 cm. 
  
 set(XMULT,xmul);
 Causes each x value to be multiplied by xmul before being 
 plotted. 
  
 set(XRANGE,xmin,ymin);
 data plotted using drawdata is constrained to have x 
 values between xmin and xmax. There is also a corresponding 
 YRANGE set option. The default is no constraints. The 
 values should be specified in user coordinates i.e. those 
 established by the current axes_box() or ascale(). 

 set(XSHIFT,xshft);
 Causes the value xshft to be added to all x values before 
 plotting. 
  
 set(YMULT,ymul);
 Causes each y value to be multiplied by ymul before being 
 plotted. 

 set(YSHIFT,yshft);
 Causes the value yshft to be added to all y values before 
 plotting. 
  

<showpage>
 void showpage();
  
 Transfers the marked page created in memory by the stroke 
 and fill commands to the physical page. This is 
 automatically done at the end of the file and thus this
 command is only needed if it is desirable to draw parts
 of the figure before the end of execution.

<smooth>
 void smooth(double *data,int col, int pnts,char wrap)

 Does a pnts point smooth on the specified column of
 the data array. The last parameter specifies that the
 data is cyclical and that to smooth the endpoints the
 algorithm should wrap around back to the beginning or
 end. The last two parameters are optional and are set
 to 5 and FALSE by default.

<splineto>
 void splineto(double x1,y1,x2,y2,...);
 or
 void splineto(double *array,int first,int last);
 or
 void splineto(double *array);

 This function accepts a list of two or more coordinate 
 pairs and using the current point as the first point draws 
 a cubic spline which goes through all of the given 
 coordinates. It uses Bezier curves internally but 
 calculates the necessary control points in order to make 
 the derivative continous everywhere. An error is generated 
 if there is no current point. Specifying less than two 
 additional points also generates an error. Several formats 
 are allowed. The first is a list of coordinate pairs. The
 second format is a pointer to a 2D array of coordinate
 pairs followed by an optional pair of integers specifying 
 the first and last pairs to be plotted.

<stroke>
 void stroke(); 
  
 Marks the page in memory with the current path. The path 
 coordinates are transformed using the current coordinate 
 transformation matrix and the path is fleshed out using the 
 current line width, style and colour in effect at the time 
 of the stroke command. 
  
<symbol>
 void symbol(double x, double y, int symbol_const); 
 or
 void symbol(int symbol_const); 

 Plots the symbol chosen by symbol_const at the point x,y. 
 symbol_const must be one of OCIRCLE, OSQUARE, OTRIANGLE, 
 ODIAMOND OSTAR, OARROW, PLUS, CROSS, MULT, CIRCLE, SQUARE, 
 TRIANGLE, DIAMOND, STAR,or ARROW. If the point x,y is 
 omitted the symbol is drawn at the current point as set 
 by a previous moveto();. symbol() is not implicitly 
 stroked so follow with a stroke();. The size of a symbol 
 can be changed using set(FONTWIDTH, val_in_cm); since 
 symbols are just a special font. The size relative to the 
 current FONTWIDTH can be set using set(SYMMULT,mult);. 

<text>
 void text(double x, double y, char * str,int just); 
  
 Adds the text string str to the current path starting at 
 location (x,y). The current font, size and orientation as 
 set using the set() command are used. Super/sub scripts can 
 be entered as ^2^ and _2_ respectively. Letters surrounded 
 by '!' or '#' are printed in Greek or italics respectively. 
 For example !m! generates the Greek lower case mu. The 
 special characters "^_!#$\" can be printed by preceding them 
 with \ as in \!. The combination \b back spaces by one 
 character. Symbols may be included in the text string by 
 enclosing them with $ as in $3$.
 If the starting x,y coordinates are omitted then 
 the current string is positioned one line below the 
 previous string added to the path using text(). The last 
 parameter is the justification and must be one of LEFT, 
 RIGHT or CENTER. This last parameter can be omitted in 
 which case the default value of LEFT will be used. text() 
 is implicitly stroked.
  
<ticklabel>
 void ticklabel(int axis, double v, char *label,...); 
  
 Add tick labels to the axes box previously defined. The 
 first parameter is which axis to label either BOTTOM, TOP, 
 LEFT or RIGHT. The following parameters are paired values 
 giving the tick position in data coordinates as established 
 by a prior call to axes_box() or ascale() and the text 
 string to be placed at that location. An error is generated 
 if there is no current axes_box. There are several default 
 possibilities. If 'ticklabel();' is called without any 
 parameters then if tick marks have been generated 
 previously using 'tickmarks();' then they will be 
 selectively labelled along the left and bottom axes. If 
 only an axis parameter is given then the corresponding axis 
 tick marks if any will be labelled. If the axis parameter 
 is followed by a list of numbers only they will be 
 assumed to be both the tick position and the desired label. 
 If the numbers are paired with strings in the parameter 
 list then the number will be used as the tick label 
 position and the string will be used as the literal label. 
 The spacing between the tick labels and the axes box can be 
 changed using set(TICKLMARG,...); ticklabel() is implicitly 
 stroked.
  
<tickmarks>
 void tickmarks(int axis, double v,...); 
  
 Add tick marks to the axes box previously defined. The 
 first parameter is which axis either BOTTOM , TOP, LEFT, 
 RIGHT ,XAXES or YAXES. The following numbers are the 
 positions were tickmarks are to to be placed. The length of 
 the ticks is set using a set(TICKLENGTH,val) command. The 
 tickmarks will be drawn using the current linestyle and 
 colour. The location of the ticks is specified in data 
 coordinates as established by the prior call to axes_box(). 
 An error is generated if there is no current axes_box. All 
 the above parameters are optional. The default behaviour is 
 as follows. If all parameters are omitted tick marks will 
 be automatically generated for all axes. If only an axis 
 specifier is given then tick marks will be generated for 
 the corresponding axis or axes. In these cases 
 'tickmarks();' will try to find reasonable positions for a 
 set of tick marks. If this default behaviour is 
 unacceptable then the actual tick positions can be 
 specified as a list of values following the axis specifier. 
 If there is only one numeric value it is interpreted as a 
 tick spacing. tickmarks() is implicitly stroked. 
  
<translate>
 void translate(double tx, double ty);
  
 Translates the origin of the 
 figure by the x and y distances
 specified. Translations are 
 cumulative.

<whereis>
 void whereis(double *x,double *y); 

 Returns the coordinates of the current point as set by the 
 last moveto(), lineto() etc.

<break>
 C keyword

 Used to prematurely terminate a loop;

 Example:

 for (i = 0;i< 100; i++)
    {
    if (cond == 1) break;
    /* if cond == 1 break out of the
    loop regardless of the value of
    i and continue at end of loop. */
    }
 
<case>
 C keyword
 
 Used in conjunction with a switch to select one of a set of 
 choices.
 
 Example:
	
  switch(code)
     {
     case 0:/* do something if code = 0*/
	    break;
     case 1:/* do this if code = 1*/
	    break;   
     case 2:
     case 3:/* do this if code = 1 or 2*/
	    break;
     default:/* do this if none of the
	       above */
	   break;
     }
 
<char>
 C keyword

 Used to allocate memory for a variable of size one byte. 
 All chars are between -128 and 127. All variable
 declarations must be done outside of the main routine for
 of the main routine for globals. Unlike standard C and more
 like C++ local variable declarations for local variables
 can be anywhere in the routine. Also specifying the size
 of local arrays using variables rather than constants is
 acceptable for the interperter.

 Example:

  char c;

 Arrays of base types can be specified using the syntax:

  char tmp[80];

 Pointers to a base type are specified as 
 
  char *tp;
 
<continue>
 C keyword
 
 Used to skip the remainder of a loop and test the condition 
 again. 
 
 Example:
 
 for (i = 0;i< 100; i++)
    {
    if (cond == 1) continue;
    /* if not cond == 1 do the rest
    of the loop below the above line
    otherwise increment i and test
    again. */
    }


<default>
 C keyword

 Used in conjunction with a switch to select the remaining
 not explicitly specified choices.

 Example:

 switch(code)
    {
    case 0:/* do something if code = 0*/
	   break;
    case 1:/* do this if code = 1*/
	   break;
    case 2:
    case 3:/* do this if code = 1 or 2*/
	   break;
    default:/* do this if none of the
	       above */
	   break;
    }

<do>
 C keyword

 Used in conjunction with while to set up loops that are
 executed at least once. For Example:

 do
    {
    /* loop body */
    }
 while (cond ==  1);

<double>
 C keyword

 Used to allocate memory for a double precision floating
 point value. All variable declarations must be done outside
 of the main routine for globals. Unlike standard C and more
 like C++ local variable declarations for local variables
 can be anywhere in the routine. Also specifying the size
 of local arrays using variables rather than constants is
 acceptable for the interperter.

 Example:

 double d;

 Arrays of base types can be specified using the syntax (2 x
 400 array):

 double data[2][400];

 Pointers to a base type are specified as

 double *tp;

<else>
 C keyword
 
 Used as part of an if statement to select the converse 
 case. Example 

 if (cond == 1)
    {
    /* execute this if cond = 1 */
    }
 else
    {
    /* execute this if cond not 1 */
    }
 
<float>
 C keyword

 Used to allocate memory for a single precision floating
 point value. All variable declarations must be done outside
 of the main routine for globals. Unlike standard C and more
 like C++ local variable declarations for local variables
 can be anywhere in the routine. Also specifying the size
 of local arrays using variables rather than constants is
 acceptable for the interperter.

 Example:

 float f;

 Arrays of base types can be specified using the syntax (2 x
 400 array):

 float data[2][400];

 Pointers to a base type are specified as:

 float *tp;

<for>
 C keyword
 
 Used to set up loops which are meant to run for a
 predetermined number of iterations. For example: 
 
 for (i = 0;i< 100; i = i + 2)
    {
    /* execute this loop body 50 
    times. i.e. until i = 100 with
    i starting at zero and incremented
    by 2 after each iteration */
    }

<int>
 C keyword

 Used to allocate memory for a variable of size one integer.
 All variable declarations must be done outside of the main
 of the main routine for globals. Unlike standard C and more
 like C++ local variable declarations for local variables
 can be anywhere in the routine. Also specifying the size
 of local arrays using variables rather than constants is
 acceptable for the interperter.

 Example:

 int i,j;

 Arrays of base types can be specified using the syntax (2 x
 400 array):

 int data[2][400];
 
 Pointers to a base type are specified
 as

 int *tp;

<if>
 C keyword
 
 Used to conditionally execute a block of code depending if 
 the conditional expression is true (non zero) or false
 (zero). Can be used in conjunction with the keyword else. 
 For example: 
 
 if (i > j && k != 10)
    {
    /* execute this block if i greater
    than j and k not equal to 10 */
    }
 else
    {
    /* otherwise to this block */
    }
 
<main>
 C keyword
 
 This is actually a function and is the starting point of 
 the code. The function main is called by hitting CTRL G. 
 The syntax is 

 main()
    {
    /* program to be executed */
    }
 
<return>
 C Keyword
 
 This exits a sub routine and returns an optional value to 
 the calling routine. For example: 
 
 main()
    {
    int x;
    i = sub(x);
    print(i);
    }
 
 int sub(int x)
    {
    /* calculate i based on input x */
    return i;
    }

<short>
 C keyword

 Used to allocate memory for a variable of size one small
 integer. All variable declarations must be done outside of
 the main of the main routine for globals. Unlike standard
 C and more like C++ local variable declarations for local
 variables can be anywhere in the routine. Also specifying
 the size of local arrays using variables rather than
 constants is acceptable for the interperter.

 Example:
 short i,j;

 Arrays of base types can be specified using the syntax (2 x
 400 array):

 short data[2][400];

 Pointers to a base type are specified as

 short *tp;

<switch>
 C keyword

 Used to select one of a number of choices based on the
 value of the expression code.

 Example:

 switch(code)
    {
    case 0:/* do something if code = 0*/
	   break;
    case 1:/* do this if code = 1*/
	   break;   
    case 2:
    case 3:/* do this if code = 1 or 2*/
	   break;
    default:/* do this if none of the
	       above */ 
	   break;
    }

<unsigned>
 C keyword

 Used as a type modifier for the integer variable types
 char, short, and int.

 example

 unsigned int ui;

<while>
 C keyword

 Used to construct loops which run an non predetermined
 number of times. For example:
 
 cond = 1;
 while (code == 1)
    {
    /* execute this loop body until
    something in here sets cond to 
    something other than 1. */
    }

