1 files changed, 37 insertions, 0 deletions
diff --git a/noao/obsutil/src/sptime/mkslit.cl b/noao/obsutil/src/sptime/mkslit.cl
new file mode 100644
index 00000000..240f851e
--- /dev/null
+++ b/noao/obsutil/src/sptime/mkslit.cl
@@ -0,0 +1,37 @@
+# MKSLIT -- Fraction of Gaussian profile going through a slit aperture
+# of specified width and height in units of the profile FWHM.
+
+real	logx, logy, t, erfcc, xval, yval
+
+printf ("## SLIT -- Fraction of Gaussian profile going through a")
+printf (" slit\n## aperture as a function of the width and height")
+printf (" in units of FWHM.\n\n")
+
+printf ("%4.2f %4.2f %5.3f\n", 0, 0, 0)
+for (logx=-1; logx<=0.6; logx=logx+0.2) {
+    x = 10.**logx
+    printf ("%4.2f %4.2f %5.3f\n", x, 0, 0)
+}
+for (logy=-1; logy<=0.6; logy=logy+0.2) {
+    y = 10.**logy
+    z = y * 0.8325546111577
+    t = 1. / (1. + 0.5 * z)
+    erfcc = t * exp (-z * z - 1.26551223 + t * (1.00002368 +
+	t * (0.37409196 + t * (0.09678418 + t * (-0.18628806 +
+	t * (0.27886807 + t * (-1.13520398 + t * (1.48851587 +
+	t * (-0.82215223 + t * 0.17087277)))))))))
+    yval = (1 - erfcc)
+    printf ("%4.2f %4.2f %5.3f\n", 0, y, 0)
+    for (logx=-1; logx<=0.6; logx=logx+0.2) {
+	x = 10.**logx
+	z = x * 0.8325546111577
+	t = 1. / (1. + 0.5 * z)
+	erfcc = t * exp (-z * z - 1.26551223 + t * (1.00002368 +
+	    t * (0.37409196 + t * (0.09678418 + t * (-0.18628806 +
+	    t * (0.27886807 + t * (-1.13520398 + t * (1.48851587 +
+	    t * (-0.82215223 + t * 0.17087277)))))))))
+	xval = (1 - erfcc)
+	z = xval * yval
+	printf ("%4.2f %4.2f %5.3f\n", x, y, z)
+    }
+}