Changeset 3105

Timestamp:

Jan 28, 2005, 5:17:26 AM (21 years ago)

Author:

eugene

Message:

minor changes

Location:

trunk/Ohana/src/opihi

Files:

• cmd.astro/imfit.c (modified) (2 diffs)
• cmd.data/Makefile (modified) (1 diff)
• cmd.data/dot.c (added)
• cmd.data/init.c (modified) (2 diffs)
• cmd.data/plot.c (modified) (1 diff)
• mana/fitcontour.c (modified) (3 diffs)

trunk/Ohana/src/opihi/cmd.astro/imfit.c

@@ -246 +246 @@
   dchisq = ochisq;
 
-  for (i = 0; (i < 50) && ((dchisq <= 0.0) || (dchisq > 0.001*(Npts - Npar))); i++) {
+  for (i = 0; (i < 25) && ((dchisq <= 0.0) || (dchisq > 0.01*(Npts - Npar))); i++) {
     chisq = mrq2dmin (x, y, z, dz, Npts, par, Npar, fitfunc, VERBOSE);
     dchisq = ochisq - chisq;
     ochisq = chisq;
   }  
+  set_int_variable ("Niter",  i);
+  
 
   if (ShapeVariation) {
@@ -407 +409 @@
   set_variable ("ChiSq", chisq/(Npts - Npar));
 
-  for (i = 0; i < Npar; i++) {
-    fprintf (stderr, "%g ", par[i]);
-  }
-  fprintf (stderr, "\n");
+  if (VERBOSE) {
+    for (i = 0; i < Npar; i++) {
+      fprintf (stderr, "%g ", par[i]);
+    }
+    fprintf (stderr, "\n");
+  }
 
   free (x);

trunk/Ohana/src/opihi/cmd.data/Makefile

@@ -72 +72 @@
 $(SDIR)/peak.$(ARCH).o          \
 $(SDIR)/plot.$(ARCH).o          \
+$(SDIR)/dot.$(ARCH).o           \
 $(SDIR)/point.$(ARCH).o         \
 $(SDIR)/ps.$(ARCH).o            \

trunk/Ohana/src/opihi/cmd.data/init.c

@@ -53 +53 @@
 int peak             PROTO((int, char **));
 int plot             PROTO((int, char **));
+int dot              PROTO((int, char **));
 int point            PROTO((int, char **));
 int pop              PROTO((int, char **));
@@ -152 +153 @@
   {"peak",         peak,             "find vector peak in range"},
   {"plot",         plot,             "plot a pair of vectors"},
+  {"dot",          dot,              "plot a single point"},
   {"point",        point,            "load overlay with single point"},
   {"ps",           ps,               "define labels for plot"},

trunk/Ohana/src/opihi/cmd.data/plot.c

@@ -123 +123 @@
 
 }
-
-

trunk/Ohana/src/opihi/mana/fitcontour.c

@@ -36 +36 @@
     r = hypot (x, y);
 
-    /* 
-    t = 2*atan2(y,x);
-    sn = sin(t);
-    cs = cos(t);
-    */
+    /* calculate sin(2t), cos(2t) using 1/2 angle tri relationship above */
     sn1 = y / r;
     cs1 = x / r;
@@ -63 +59 @@
   gaussj (C, NTERM, B, 1);
   
+  /** this is somewhat weak: if the object is too elongated, Rmin can be < 0 **/
   dR = hypot (B[1][0], B[2][0]);
   Rmaj = B[0][0] + dR;
@@ -101 +98 @@
 }
 
+
+/* this routine fits a single sine and cosine to the value of dr as a function of the angle around the central
+ * point, theta.  this is NOT an exact fit, an is increasingly in error for more eccentric ellipses.  however,
+ * it does a reasonable job of approximating the value of the major and minor axes, and it gets the angle of
+ * orientation right at well.  We then assume the values of major and minor axis and angle are correct to get
+ * the parameters for the elliptical gaussian fit:
+ 
+ z = (x^2) / (2 Rx^2) + (y^2) / (2 Ry^2) + Rxy x y
+
+ the functions above give the correct relationship between these:
+
+   R1 = SQ(Rmaj) + SQ(Rmin);
+   R2 = SQ(Rmaj) - SQ(Rmin);
+   R3 = Rmaj*Rmin;
+
+   Rx = R3 / sqrt (R1 - R2*cs);
+   Ry = R3 / sqrt (R1 + R2*cs);
+   Rxy = -sn*R2 / SQ(R3);
+
+ to derive these relationships, write the equation for an ellipse with major axis in the x-dir and minor in
+ the y-dir:
+
+ z = (x^2) / (2 Rmaj^2) + (y^2) / (2 Rmin^2)
+
+ apply the rotation matrix:
+
+ (x)' = (cos, -sin)(x,y)
+ (y)' = (sin, +cos)(x,y)  (modulo the sign on the sine)
+
+ then group the x^2 terms, the y^2 terms, and the xy terms to find the three coeffs.
+
+ NOTE: I spent a while having trouble deriving this from the polar form of an ellipse:
+
+ x = Rmaj*cos(theta)
+ y = Rmin*sin(theta)
+
+ it turns out that 'theta' above is NOT the angle (0,1)-(0,0)-(x,y). rather, it should be viewed as a
+ paraterization of the ellipse.  
+
+*/