## functions in graph.i - t

triangle

triangle= plotting keyword sets the triangulation array for a contour plot. The triangulation array must be the same shape as the IREG (region number) array, and the correspondence between mesh zones and indices is the same as for IREG. The triangulation array is used to resolve the ambiguity in saddle zones, in which the function Z being contoured has two diagonally opposite corners high, and the other two corners low. The triangulation array element for a zone is 0 if the algorithm is to choose a triangulation, based on the curvature of the first contour to enter the zone. If zone (i,j) is to be triangulated from point (i-1,j-1) to point (i,j), then TRIANGLE(i,j)=1, while if it is to be triangulated from (i-1,j) to (i,j-1), then TRIANGLE(i,j)=-1. Contours will never cross this "triangulation line". You should rarely need to fiddle with the traingulation array; it is a hedge for dealing with pathological cases. PLOTTING COMMANDS: plc Keyword, defined at i0/graph.i line 1149

type

type= plotting keyword selects line type. Valid values are the strings "solid", "dash", "dot", "dashdot", "dashdotdot", and "none". The "none" value causes the line to be plotted as a polymarker. You should also check the plmk function if you need polymarkers. The type value may also be a number; 0 is "none", 1 is "solid", 2 is "dash", 3 is "dot", 4 is "dashdot", and 5 is "dashdotdot". PLOTTING COMMANDS: plg, plm, plc, pldj Keyword, defined at i0/graph.i line 948SEE ALSO: width, color, marks, marker, rays, closed, smooth, plmk