Initial commit

1 files changed, 45 insertions, 0 deletions

diff --git a/local/src/pavg.x b/local/src/pavg.x
new file mode 100644
index 00000000..7124c4d0
--- /dev/null
+++ b/local/src/pavg.x
@@ -0,0 +1,45 @@
+include <imhdr.h>
+
+# PAVG -- CL callable task to plot the average of the lines of an image or
+# image section on the standard graphics output.  This example is taken from
+# the IRAF paper.
+
+procedure t_pavg()
+
+char    image[SZ_FNAME]         # name of image to be plotted
+char    title[SZ_LINE]
+int     npix, nlines
+long    v[IM_MAXDIM]
+pointer im, lineptr, sumv
+pointer immap(), imgnlr()
+
+begin
+        # Fetch image name from CL and open the image.  The IMMAP
+        # function returns a pointer to the image descriptor structure.
+
+        call clgstr ("image", image, SZ_FNAME)
+        im = immap (image, READ_ONLY, 0)
+
+        # Allocate a zeroed buffer of length NPIX for the sum-vector,
+        # and set V to point to first image line, i.e., v=[1,1,1,...].
+
+        npix = IM_LEN(im,1)
+        call calloc (sumv, npix, TY_REAL)
+        call amovkl (long(1), v, IM_MAXDIM)
+
+        # Sum the lines of the image.
+        for (nlines=0;  imgnlr(im,lineptr,v) != EOF;  nlines=nlines+1)
+            call aaddr (Memr[lineptr], Memr[sumv], Memr[sumv], npix)
+
+        # Normalize the sum-vector to get the average.
+        call adivkr (Memr[sumv], real(nlines), Memr[sumv], npix)
+
+        # Format plot title and plot the sum-vector on STDGRAPH.
+        call sprintf (title, SZ_LINE, "Line Average of %s")
+            call pargstr (image)
+        call gplotv (Memr[sumv], npix, 1., real(npix), title)
+
+        # Free storage for sum-vector and close image.
+        call mfree (sumv, TY_REAL)
+        call imunmap (im)
+end