Changeset 37510 for trunk/psLib

Timestamp:

Oct 20, 2014, 5:25:31 PM (12 years ago)

Author:

watersc1

Message:

Change in scaling. If we have a median that is identically 0.0, we need to change it to something else to prevent problems in the unscaling code (there's a median(power) term. If the sigma is equally bad, simply don't scale, and hope for the best. Otherwise, choose an arbitrary small offset that's a fixed fraction of the sigma value, as we do want to scale bad ranged data, even if it is centered around zero.

File:

• trunk/psLib/src/math/psMinimizePolyFit.c (modified) (2 diffs)

trunk/psLib/src/math/psMinimizePolyFit.c

@@ -731 +731 @@
           scale = false;
         }
+
+        if (median == 0.0) {
+          if (sigma <= 0.0) {
+            scale = false; // Try with what we started with.
+          }
+          else {
+            median = 0.1 * sigma;
+          }
+        }
+
         // I can't see a way to not clobber x if it's already F64, so make a copy.x
         psVector *z64 = psVectorCopy(NULL,x64,PS_TYPE_F64);
@@ -740 +750 @@
 #endif
 
-        
         result = VectorFitPolynomial1DOrd(poly, mask, maskValue, f64, fErr64, z64);
         psFree(z64); // Done with this.