1 files changed, 61 insertions, 0 deletions
diff --git a/sys/imio/imsamp.x b/sys/imio/imsamp.x
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+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+# IMSAMP -- Subsample a vector.
+
+procedure imsamp (a, b, npix, sz_pixel, step)
+
+char	a[ARB], b[ARB]
+int	npix, sz_pixel, step, i, j, in, out, delta_in
+
+begin
+	switch (sz_pixel) {
+	case SZ_SHORT:
+	    call imsmps (a, b, npix, step)
+	case SZ_LONG:
+	    call imsmpl (a, b, npix, step)
+
+	default:				# flip odd sized elements
+	    in = 0
+	    out	= 0
+	    delta_in = sz_pixel * step
+
+	    do j = 1, npix {
+		do i = 1, sz_pixel
+		    b[out+i] = a[in+i]
+		in = in + delta_in
+		out = out + sz_pixel
+	    }
+	}
+end
+
+
+# IMSMPS -- Sample an array of SHORT sized elements.
+
+procedure imsmps (a, b, npix, step)
+
+short	a[ARB], b[npix]
+int	npix, step, ip, op
+
+begin
+	ip = 1
+	do op = 1, npix {
+	    b[op] = a[ip]
+	    ip = ip + step
+	}
+end
+
+
+# IMSMPL -- Sample an array of LONG sized elements.
+
+procedure imsmpl (a, b, npix, step)
+
+long	a[ARB], b[npix]
+int	npix, step, ip, op
+
+begin
+	ip = 1
+	do op = 1, npix {
+	    b[op] = a[ip]
+	    ip = ip + step
+	}
+end