1 files changed, 82 insertions, 0 deletions
diff --git a/pkg/xtools/gtools/gtplot.x b/pkg/xtools/gtools/gtplot.x
new file mode 100644
index 00000000..3591e6ab
--- /dev/null
+++ b/pkg/xtools/gtools/gtplot.x
@@ -0,0 +1,82 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<gset.h>
+include	"gtools.h"
+
+# GT_GRAPH -- Plot polymarks or polypoints.
+
+procedure gt_plot (gp, gt, x, y, npts)
+
+pointer	gp		# GIO pointer
+pointer	gt		# GTOOLS pointer
+real	x[npts]		# Abscissas
+real	y[npts]		# Ordinates
+int	npts		# Number of points
+
+int	i, color, pltype, gstati()
+real	x1, x2
+
+begin
+	switch (GT_TYPE(gt)) {
+	case 1:
+	    #color = gstati (gp, G_PMCOLOR)
+	    #call gseti (gp, G_PMCOLOR, GT_COLOR(gt))
+	    color = gstati (gp, G_PLCOLOR)
+	    call gseti (gp, G_PLCOLOR, GT_COLOR(gt))
+	    if (GT_TRANSPOSE(gt) == NO)
+	        call gpmark (gp, x, y, npts, GT_MARK(gt), GT_XSIZE(gt),
+		    GT_YSIZE(gt))
+	    else
+	        call gpmark (gp, y, x, npts, GT_MARK(gt), GT_YSIZE(gt),
+		    GT_XSIZE(gt))
+	    #call gseti (gp, G_PMCOLOR, color)
+	    call gseti (gp, G_PLCOLOR, color)
+	case 2:
+	    color = gstati (gp, G_PLCOLOR)
+	    call gseti (gp, G_PLCOLOR, GT_COLOR(gt))
+	    pltype = gstati (gp, G_PLTYPE)
+	    call gseti (gp, G_PLTYPE, GT_LINE(gt))
+	    if (GT_TRANSPOSE(gt) == NO)
+	        call gpline (gp, x, y, npts)
+	    else
+	        call gpline (gp, y, x, npts)
+	    call gseti (gp, G_PLTYPE, pltype)
+	    call gseti (gp, G_PLCOLOR, color)
+	case 3:
+	    color = gstati (gp, G_PLCOLOR)
+	    call gseti (gp, G_PLCOLOR, GT_COLOR(gt))
+	    pltype = gstati (gp, G_PLTYPE)
+	    call gseti (gp, G_PLTYPE, GT_LINE(gt))
+	    if (GT_TRANSPOSE(gt) == NO) {
+		x1 = x[1]
+		x2 = (x[1] + x[2]) / 2
+		call gline (gp, x1, y[1], x2, y[1])
+		do i = 2, npts - 1 {
+		    x1 = x2
+		    x2 = (x[i] + x[i+1]) / 2
+		    call gline (gp, x1, y[i-1], x1, y[i]) 
+		    call gline (gp, x1, y[i], x2 , y[i])
+		}
+		x1 = x2
+		x2 = x[npts]
+		call gline (gp, x1, y[i-1], x1, y[i]) 
+		call gline (gp, x1, y[i], x2 , y[i])
+	    } else {
+		x1 = y[1]
+		x2 = (y[1] + y[2]) / 2
+		call gline (gp, x1, x[1], x2, x[1])
+		do i = 2, npts - 1 {
+		    x1 = x2
+		    x2 = (y[i] + y[i+1]) / 2
+		    call gline (gp, x1, x[i-1], x1, x[i]) 
+		    call gline (gp, x1, x[i], x2 , x[i])
+		}
+		x1 = x2
+		x2 = y[npts]
+		call gline (gp, x1, y[i-1], x1, y[i]) 
+		call gline (gp, x1, y[i], x2 , y[i])
+	    }
+	    call gseti (gp, G_PLTYPE, pltype)
+	    call gseti (gp, G_PLCOLOR, color)
+	}
+end