Changeset 20794

Timestamp:

Nov 18, 2008, 5:49:40 PM (17 years ago)

Author:

eugene

Message:

a bit more rigorous on minimum number of detections for an N-order fit

File:

• trunk/psastro/src/psastroOneChipFit.c (modified) (1 diff)

trunk/psastro/src/psastroOneChipFit.c

@@ -51 +51 @@
 
         // modify the order to correspond to the actual number of matched stars:
-        if ((match->n < 11) && (order >= 3)) order = 2;
-        if ((match->n <  7) && (order >= 2)) order = 1;
-        if ((match->n <  4) && (order >= 1)) order = 0;
+        int Ndof_min = 3;
+        int order_max = 0.5*(3 + sqrt(4*match->n - 4*Ndof_min + 1));
+        order = PS_MIN (order, order_max);
+
+        // if ((match->n < 11) && (order >= 3)) order = 2;
+        // if ((match->n <  7) && (order >= 2)) order = 1;
+        // if ((match->n <  4) && (order >= 1)) order = 0;
+
         if (order < 1) {
             psLogMsg ("psastro", 3, "insufficient stars or invalid order: %ld stars", match->n);