Changeset 29011 for trunk/ppSim/src/ppSimMakeGalaxies.c

Timestamp:

Aug 23, 2010, 7:26:50 AM (16 years ago)

Author:

eugene

Message:

add option to change output image size (not yet working); fix scale parameters for random galaxies

File:

• trunk/ppSim/src/ppSimMakeGalaxies.c (modified) (4 diffs)

trunk/ppSim/src/ppSimMakeGalaxies.c

@@ -109 +109 @@
                 // galaxy->index = (1/2n)
 
-                float factor = galaxyGridRandom ? drand48() : i / num;
-                float index = (galaxyIndexMin  + factor * galaxyIndexSlope); // factor of 0.5 because the Sersic model creates exp(-z^n), not exp(-r^n)
-                galaxy->index = 0.5/index;
+                float rndValue;
 
-                factor = galaxyGridRandom ? drand48() : i / num;
-                float scale = (galaxyRmajorMin + factor * galaxyRmajorSlope);
+                rndValue = galaxyGridRandom ? drand48() : i / num;
+                float index = (galaxyIndexMin  + rndValue * galaxyIndexSlope);
+                galaxy->index = 0.5/index; // factor of 0.5 because the Sersic model creates exp(-z^n), not exp(-r^n)
+
+                rndValue = galaxyGridRandom ? drand48() : i / num;
+                float scale = (galaxyRmajorMin + rndValue * galaxyRmajorSlope);
 
                 // for a sersic model, 
@@ -121 +123 @@
                 float Io = exp(bn);
 
-                // galaxy->Rmaj  = scale * fR;
-
                 galaxy->Rmaj  = scale;
 
-                factor = galaxyGridRandom ? drand48() : i / num;
-                galaxy->Rmin  = (galaxyARatioMin + factor * galaxyARatioSlope) * galaxy->Rmaj;
+                rndValue = galaxyGridRandom ? drand48() : i / num;
+                galaxy->Rmin  = (galaxyARatioMin + rndValue * galaxyARatioSlope) * galaxy->Rmaj;
 
-                factor = galaxyGridRandom ? drand48() : i / num;
-                galaxy->theta = (galaxyThetaMin  + factor * galaxyThetaSlope);
+                rndValue = galaxyGridRandom ? drand48() : i / num;
+                galaxy->theta = (galaxyThetaMin  + rndValue * galaxyThetaSlope);
 
                 // galaxy->peak *= Io;
@@ -158 +158 @@
             galaxy->y    = psRandomUniform(rng) * ySize; // y position
 
-            // galaxy->flux = pow ((double)((i + 1) / norm), (double) (1.0 / galaxyLum));
+            float index = (sqrt(psRandomUniform(rng)) * galaxyIndexSlope  + galaxyIndexMin);
+            galaxy->index = 0.5/index; // factor of 0.5 because the Sersic model creates exp(-z^n), not exp(-r^n)
 
-            galaxy->index = (sqrt(psRandomUniform(rng)) * galaxyIndexSlope  + galaxyIndexMin);
+            float scale = (psRandomUniform(rng) * galaxyRmajorSlope + galaxyRmajorMin);
+
+            // for a sersic model, 
+            float bn = 1.9992*index - 0.3271;
+            float fR = 1.0 / (sqrt(2.0) * pow (bn, index));
+            float Io = exp(bn);
+
+            galaxy->Rmaj  = scale;
+
+            galaxy->Rmin  = (PS_SQR(psRandomUniform(rng)) * galaxyARatioSlope + galaxyARatioMin) * galaxy->Rmaj;
+
             galaxy->theta = (psRandomUniform(rng) * galaxyThetaSlope  + galaxyThetaMin);
-            galaxy->Rmaj  = (psRandomUniform(rng) * galaxyRmajorSlope + galaxyRmajorMin);
-            galaxy->Rmin  = (PS_SQR(psRandomUniform(rng)) * galaxyARatioSlope + galaxyARatioMin) * galaxy->Rmaj;
 
             // the flux is only approximately correct (scaling of the peak is wrong)
@@ -170 +179 @@
             galaxy->peak = galaxy->flux / (2.0*M_PI*PS_SQR(seeing));
 
+            if (0) {
+              fprintf (stderr, "Rmaj: %f, scale: %f, index: %f, bn: %f, Ro: %f, Io: %f\n", galaxy->Rmaj, scale, index, bn, fR, Io);
+            }
+
             psArrayAdd (galaxies, 100, galaxy);
         }