section c of routines in graph.i

functions in graph.i - c

closed


    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 1071

SEE ALSO: type, width, color, marks, marker, rays

color


    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 969

SEE ALSO: type, width, marks, marker, mcolor, rays, closed, smooth

color_bar


    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 1786

SEE ALSO: plfc

contour


    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 505