Changeset 14325 for trunk/psModules/src/objects/models/pmModel_SERSIC.c

Timestamp:

Jul 19, 2007, 2:31:43 PM (19 years ago)

Author:

magnier

Message:

fixed minor bugs

File:

• trunk/psModules/src/objects/models/pmModel_SERSIC.c (modified) (4 diffs)

trunk/psModules/src/objects/models/pmModel_SERSIC.c

@@ -51 +51 @@
 
     psF32 f2 = pow(z,PAR[PM_PAR_7]);
-    psF32 f1 = exp(-z);
+    psF32 f1 = exp(-f2);
     psF32 z0 = PAR[PM_PAR_I0]*f1;
     psF32 f0 = PAR[PM_PAR_SKY] + z0;
 
+    assert (isfinite(f2));
+    assert (isfinite(f1));
+    assert (isfinite(z0));
+    assert (isfinite(f0));
+
     if (deriv != NULL) {
         psF32 *dPAR = deriv->data.F32;
 
-        // note difference from a pure gaussian: q = params->data.F32[PM_PAR_I0]*r
-        psF32 z1 = z0*PAR[PM_PAR_7]*pow(z,PAR[PM_PAR_7] - 1.0);
+        // gradient is infinite for z = 0; saturate at z = 0.01
+        psF32 z1 = (z < 0.01) ? z0*PAR[PM_PAR_7]*pow(0.01,PAR[PM_PAR_7] - 1.0) : z0*PAR[PM_PAR_7]*pow(z,PAR[PM_PAR_7] - 1.0);
 
         dPAR[PM_PAR_SKY]  = +1.0;
         dPAR[PM_PAR_I0]   = +f1;
         dPAR[PM_PAR_7]    = (z == 0.0) ? 0.0 : -z0*f2*log(z);
+
+        assert (isfinite(z1));
+        assert (isfinite(dPAR[PM_PAR_7]));
 
         dPAR[PM_PAR_XPOS] = +1.0*z1*(2.0*px/PAR[PM_PAR_SXX] + Y*PAR[PM_PAR_SXY]);
@@ -70 +78 @@
         dPAR[PM_PAR_SYY]  = +2.0*z1*py*py/PAR[PM_PAR_SYY];
         dPAR[PM_PAR_SXY]  = -1.0*z1*X*Y;
-    }
-    return(f);
+        dPAR[PM_PAR_SXY]  = -1.0*z1*X*Y;
+    }
+    return (f0);
 }
 
@@ -156 +165 @@
             break;
         case PM_PAR_7:
-            params_min =   0.1;
+            params_min =   0.25;
             break;
         default:
@@ -244 +253 @@
     PAR[PM_PAR_SYY]  = PS_MAX(0.5, M_SQRT2*shape.sy);
     PAR[PM_PAR_SXY]  = shape.sxy;
-    PAR[PM_PAR_7]    = 1.0;
+    PAR[PM_PAR_7]    = 0.5;
 
     return(true);