Changeset 500

Timestamp:

02/23/05 13:59:06 (20 years ago)

Author:

kil064

Message:

rotateXYPhase -> rotatePhase
add function rotateLinPolPgase

Location:

trunk/src

Files:

• SDPol.cc (modified) (1 diff)
• SDPol.h (modified) (1 diff)

trunk/src/SDPol.cc

@@ -271 +271 @@
                                        const Array<Float>& U)
 {
-   return Float(180.0/C::pi/2.0)*atan2(Q,U);       // Degrees
-}
-
-
-void SDPolUtil::rotateXYPhase (Array<Float>& C3,
-                               Array<Float>& C4,
-                               Float phase)
+   return Float(180.0/C::pi/2.0)*atan2(U,Q);       // Degrees
+}
+
+
+void SDPolUtil::rotatePhase (Array<Float>& R,
+                             Array<Float>& I,
+                             Float phase)
+//
+// Apply phase rotation to Z = (R + iI)
+//
 {
    Float cosVal = cos(C::pi/180.0*phase);
    Float sinVal = sin(C::pi/180.0*phase);
 //
-   C3 = C3*cosVal - C4*sinVal;
-   C4 = C3*sinVal + C4*cosVal;
-}
+   Array<Float> R2 = R*cosVal - I*sinVal;
+   I =  R*sinVal + I*cosVal;
+   R = R2;
+}
+
+
+void SDPolUtil::rotateLinPolPhase (Array<Float>& C1,
+                                   Array<Float>& C2,
+                                   Array<Float>& C3,
+                                   Array<Float>& I,
+                                   Array<Float>& Q,
+                                   Array<Float>& U,
+                                   Float phase)
+//
+// Rotate P = Q + iU but do it directly on the  linear
+// correlations.
+//
+// We are using I=(XX+YY)/2 convention
+// C1 = XX; C2 = YY, C3 = Real(XY)
+//
+{
+// Rotate Q & U (factor of 2 for polarization)
+
+   rotatePhase(Q, U, 2.0*phase);
+
+// Now recompute C1,C2,C3 
+// C4 unchanged 
+
+   C1 = I + Q;
+   C2 = I - Q;
+   C3 = U;
+}
+
+
 
 

trunk/src/SDPol.h

@@ -155 +155 @@
                                                  const casa::Array<casa::Float>& U);
 
- // Rotate phase of Complex correlation C3+iC4 by phase (degrees)
-  static void rotateXYPhase (casa::Array<casa::Float>& C3,
-                             casa::Array<casa::Float>& C4,
-                             casa::Float phase);
+ // Rotate phase of Complex correlation R+iI by phase (degrees)
+  static void rotatePhase (casa::Array<casa::Float>& R,
+                           casa::Array<casa::Float>& I,
+                           casa::Float phase);
+
+ // Rotate phase of P=(Q+iU) by phase (degrees), but do this by applying 
+ // the corrections to the raw linear polarizations
+  static void rotateLinPolPhase (casa::Array<casa::Float>& C1,
+                                 casa::Array<casa::Float>& C2,
+                                 casa::Array<casa::Float>& C3,
+                                 casa::Array<casa::Float>& I,
+                                 casa::Array<casa::Float>& Q,
+                                 casa::Array<casa::Float>& U,
+                                 casa::Float phase);
 
 // Get Stokes slices from the Array.  Start and End should