18.20  TDHIST 

Does histograms
     CALL TDHIST(Npts,X,Y[,DX[,DY[,LEVEL[,MODE[,Z[,DZ]]]]]])
     1.  Npts - Then number of points to plot
     2.  X(Npts) - The X for each datum to histogram
     3.  Y(Npts) - The Y for each datum
     4.  DX(Npts) - The Error in X
     5.  DY(Npts) - The Error in Y
     6.  LEVEL     = 0 Histogram
                   = 1 BARCHART
     7.  MODE  -  Selects  the line structure,color,intensiy If zero these
         are set by the SET command.
           Intensity*8 (Intensity=1 to 5)
           1*64,   2*64,    3*64,  4*64,  5*64,      6*64,    7*64
             64,    128,     192,   256,   320,       384,     448
           DOTS, DASHES, DOTDASH, SOLID, FUNNY, PATTERNED, DAASHES
           WHITE   RED GREEN  BLUE YELLOW MAGENTA CYAN 
           1*512 2*512 3*512 4*512 5*512  6*512  7*512
     8.  Z(Npts) - The Z for each datum
     9.  DZ(Npts) - The Error in Z