functions in graph.i - c

             closed=   plotting keyword  
          or smooth=   plotting keyword  
 
     selects closed curves (closed=1) or default open curves (closed=0),  
     or Bezier smoothing (smooth>0) or default piecewise linear curves  
     (smooth=0).  The value of smooth can be 1, 2, 3, or 4 to get  
     successively more smoothing.  Only the Bezier control points are  
     plotted to an X window; the actual Bezier curves will show up in  
     PostScript hardcopy files.  Closed curves join correctly, which  
     becomes more noticeable for wide lines; non-solid closed curves  
     may look bad because the dashing pattern may be incommensurate  
     with the length of the curve.  
   PLOTTING COMMANDS: plg, plc (smooth only)  

keyword,  defined at i0/graph.i   line 951  

             color=   plotting keyword  
 
     selects line or text color.  Valid values are the strings "bg", "fg",  
     "black", "white", "red", "green", "blue", "cyan", "magenta", "yellow",  
     or a 0-origin index into the current palette.  The default is "fg".  
     Negative numbers may be used instead of the strings: -1 is bg  
     (background), -2 is fg (foreground), -3 is black, -4 is white,  
     -5 is red, -6 is green, -7 is blue, -8 is cyan, -9 is magenta, and  
     -10 is yellow.  (The negative numbers are actually taken modulo  
     256, so -1 is also 255, -2 is 254, and so on.)  
     A color can also be a triple [r, g, b], with values running from  
     0 for dark to 255 for full intensity.  Beware, however, of  
     specifying an rgb color (either as a color keyword or to the  
     plf, pli, or plfp commands) if your display is not a true color  
     display (for example, if it is 8 bits deep or less).  In that  
     case, it may switch to a 5x9x5 color cube, which causes a  
     significant degradation in quality of rendering with smooth  
     color palettes.  Furthermore, the hcp command will not work  
     properly for rgb colors if the file is a CGM.  Use the rgb=1  
     keyword in the window command to avoid having to re-issue a  
     palette command after the first rgb object is drawn (this is  
     unnecessary on true color screens).  
   PLOTTING COMMANDS: plg, plm, plc, pldj, plt  

keyword,  defined at i0/graph.i   line 849  

             color_bar  
          or color_bar, levs, colors  
 
     Draw a color bar below the current coordinate system.  If LEVS is  
     not specified uses plfc_levs (set by previous call to plfc).  If  
     COLORS is specified, it should have one more value than LEVS,  
     otherwise equally spaced colors are chosen, or plfc_colors if  
     plfc_levs was used.  With the vert=1 keyword the color bar appears  
     to the left of the current coordinate system (vert=0 is default).  
     By default, color_bar will attempt to label some of the color  
     interfaces.  With the labs= keyword, you can force the labelling  
     algorithm as follows: labs=0 supresses all labels, labs=n forces  
     a label at every nth interface, labs=[i,n] forces a label at every  
     nth interface starting from interface i (0<=i<=numberof(LEVS)).  
     You can use the adjust= keyword to move the bar closer to (adjust<0)  
     or further from (adjust>0) the viewport, and the height= keyword to  
     set the height of any labels (default 14 points).  

interpreted function, defined at i0/graph.i   line 1648  

             nc= contour(yc,xc, level, z, y,x)  
          or nc= contour(yc,xc, level, z, y,x,ireg)  
 
     returns the points on the contour curve that would have been  
     plotted by plc.  Z, Y, X, and IREG are as for plc, and the  
     triangle= and region= keywords are accepted and have the same  
     meaning as for plc.  Unlike plc, the triangle array is an output  
     as well as an input to contour; if supplied it may be modified  
     to reflect any triangulations which were performed by contour.  
     LEVEL is a scalar z value to return the points at that contour  
     level.  All such points lie on edges of the mesh.  If a contour  
     curve closes, the final point is the same as the initial point  
     (i.e.- that point is included twice in the returned list).  
     LEVEL is a pair of z values [z0,z1] to return the points of  
     a set of polygons which outline the regions between the two  
     contour levels.  These will include points on the mesh boundary  
     which lie between the levels, in addition to the edge points  
     for both levels.  The polygons are closed, simply connected,  
     and will not contain more than about 4000 points (larger polygons  
     are split into pieces with a few points repeated where the pieces  
     join).  
     YC and XC are the output points on the curve(s), or nil if there  
     are no points.  On input, they must be simple variable references,  
     not expressions.  The return value NC is a list of the lengths of  
     the polygons/polylines returned in (XC,YC), or nil if there are  
     none.  numberof(XC)==numberof(YC)==sum(NC).  For the level pair  
     case, YC, XC, and NC are ready to be used as inputs to plfp.  
   KEYWORDS: triangle, region  

builtin function, documented at i0/graph.i   line 392  

             n= current_window()  
 
     returns the number of the current graphics window, or -1 if none.  

builtin function, documented at i0/graph.i   line 106