Changeset 17616 for trunk/ppSim/src/ppSimMakeStars.c

Timestamp:

May 9, 2008, 11:37:58 AM (18 years ago)

Author:

eugene

Message:

option for flat magnitude distribution

File:

• trunk/ppSim/src/ppSimMakeStars.c (modified) (3 diffs)

trunk/ppSim/src/ppSimMakeStars.c

@@ -24 +24 @@
     float seeing       = psMetadataLookupF32(&status, recipe, "SEEING"); // Seeing SIGMA (pixels)
     float scale        = psMetadataLookupF32(&status, recipe, "SCALE") * M_PI / 3600.0 / 180.0; // Plate scale (radians/pixel)
+
+    bool flatLum       = psMetadataLookupBool(&status,recipe, "STARS.FLAT.LUM"); // were real stars generated?
+    float flatNum      = psMetadataLookupS32(&status, recipe, "STARS.FLAT.NUM"); // were real stars generated?
 
     float skyRate = psMetadataLookupF32(&status, recipe, "SKY.RATE"); // Sky rate
@@ -93 +96 @@
 
     // Total number of stars down to the faint flux end
-    long nTotal = normScale * powf (10.0, (starsAlpha * faintMag));
+    long nTotal = 0;
+    if (flatLum) {
+        nTotal = flatNum;
+    } else {
+        nTotal = normScale * powf (10.0, (starsAlpha * faintMag));
+    }
 
-    psLogMsg("ppSim", PS_LOG_INFO, "Adding %ld stars down to %f mag\n", nTotal, faintMag);
+    psLogMsg("ppSim", PS_LOG_INFO, "Adding %ld stars between %f and %f mag\n", nTotal, brightMag, faintMag);
 
     long oldSize = stars->n;
@@ -107 +115 @@
         star->y    = psRandomUniform(rng) * ySize; // y position
 
-        // XXX this needs to respect the bright limit
-        float starMag = log10((i + 1.0) / normScale) / starsAlpha;
+        float starMag = 0;
+        if (flatLum) {
+            starMag = psRandomUniform(rng) * (faintMag - brightMag) + brightMag;
+        } else {
+            starMag = PS_MIN (faintMag, PS_MAX (brightMag, (log10((i + 1.0) / normScale) / starsAlpha)));
+        }
         
         star->flux = ppSimMagToFlux (starMag, zp) * expTime;