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- { SCCSid "@(#)source.cal 2.3 8/18/92 LBL" }
-
- {
- Source distribution coordinates (degrees).
-
- Theta is measured from the negative z-axis,
- phi is measured from the positive x-axis
- according to the right-hand rule.
-
- srcB_vert and srcB_horiz are angles
- used in type B photometry.
-
- boxcorr function corrects for distribution modeled
- with a rectangular box. lboxcorr provides a more
- accurate calculation for nearby surfaces, but requires
- that the source box be centered at the origin.
-
- A1 - optional multipier
- A2,A3,A4 - X,Y,Z dimensions of axis-aligned box
- }
- { local definitions }
- boxprojection = abs(Dx)*A3*A4 + abs(Dy)*A2*A4 + abs(Dz)*A2*A3;
- lboxprojection = ( noneg(abs(Px-Dx*Ts)-A2/2)*A3*A4 +
- noneg(abs(Py-Dy*Ts)-A3/2)*A2*A4 +
- noneg(abs(Pz-Dz*Ts)-A4/2)*A2*A3 ) / Ts;
-
- flatcorr(v) = corr(v) / Rdot; { correction for flat sources }
- corr(v) = if(AC-.5, A1*v, v); { multiplier correction }
- boxcorr(v) = A1 * v / boxprojection; { correction for emitting box }
- lboxcorr(v) = A1 * v / lboxprojection; { local box correction }
-
- src_theta = Acos(Dz) / DEGREE; { 0-180 }
- src_phi = mod( atan2(Dy, Dx) / DEGREE, 360 ); { 0-360 }
- { bilateral symmetry }
- src_phi2 = tri( src_phi, 180 ); { 0-180 }
- { quadrilateral symmetry }
- src_phi4 = tri( src_phi, 90 ); { 0-90 }
-
- { Type B photometry coordinates }
- srcB_vert = atan( -Dx/Dz ) / DEGREE;
- srcB_horiz = Asin(Dy) / DEGREE;
- { w/ bilateral symmetry }
- srcB_horiz2 = abs( srcB_horiz );
-