functions in graph.i - t

             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 1086  

             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 885