<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 'Exec' 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. 


    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. 

<product_info>
 This is Splot version 1.2.0

 THIS PROGRAM WAS WRITTEN BY THOMAS W. STEINER
 COPYRIGHT 1992 - 1994, 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
	312 - 1230 Haro St.
     Vancouver, BC, V6E - 4J9  
	      Canada
       e-mail steiner@sfu.ca

 Registered users will receive upgrades
 as they become available
 
<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. 
 
<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 degrees. 
 
<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. 
 
<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. 
 
<sin>
 double sin(double x);
 
 Returns the sine of x. x must be specified in degrees. 
 
<sqrt>
 double sqrt(double x);
 
 Calculates the square root of x. x must be a positive 
 number. 
 
<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. 
 
<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 degrees. 
 
<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. 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. 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 previous line in the current path. 
 
<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. 
 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); 
  
 Adds a Bezier curve section 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. 
  
<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. drawdata() is implicitly stroked.

<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.
  
<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. 

<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,...); 
  
 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. 
  
<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. 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. 
  
<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); 
  
 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. 
  
  
<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,...); 
  
 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. 
  
<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.
  
<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.
  
<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 
 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 
 globals or immediately after the function declaration for 
 local variables. 
 
 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 or immediately after the 
 function declaration for local variables. 
 
 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 or immediately after the 
 function declaration for local variables. 
 
 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 
 routine for globals or immediately after the function 
 declaration for local variables. 
 
 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;
    }
 
<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;
    }
 
<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. */
    }
 
 
