Function: BEAM Purpose: Draw elliptical shaded beam (PGPLOT) Category: PLOTTING File: beam.c Author: M. Vogelaar Use: INTEGER BEAM( SET, Input character*(*) SUBSET, Input integer SPATIAL, Input integer DELTA, Input double precision array CENTREXY, Input double precision array FWHMMAJ, Input double precision FWHMMIN, Input double precision PA, Input double precision LINES, Input integer SLOPE Input double precision SHAPE ) Input integer BEAM Returns: 0 successful -1 No valid shape selected -2 No sky coordinates found in set -3 Cannot find the grids for this beam! SET GDS set (as returned by GDSINP). SUBSET A single subset (as returned by GDSINP). SPATIAL = 1 if both subset axes are spatial = 0 other combinations DELTA Grid spacing in X and Y. In the calling environment this parameter is set to header values of cdelt or ddelt or the parameter is calculated some other way. CENTREXY X and Y position of centre of ellipse in world coordinates/grids. FWHMMAJOR FWHM major axis of ellipse in degrees! FWHMMINOR FWHM minor axis of ellipse in degrees! PA Position angle of ellipse wrt. north in the direction of the east, in degrees. LINES Approximation of number of shading lines for ellipse. SLOPE Slope of shading lines in degrees. This slope is defined in the system of the grids i.e. slope = 0 is draws shading line parallel to the X axis. SHAPE 1: Plot shaded ellipse 2: Plot rectangle (e.g.IRAS beam) 3: Plot cross Description: Draw an beam with an elliptical or rectangular shape or a cross with specifications (origin, axes and projection angle). The beam axes are specified in degrees and all calculated ellipse coordinates are transformed to grids using the transformation formulas for sky system and projection. The position angle of the major axis is wrt. +m axis. This angle is corrected for the rotation of the image (CROTA). If user wants shading (parallel line pattern only) you can give the slope of the lines (wrt +X axis) in 'SLOPE' and the approximate number of shade lines in 'DELTA'. Updates: Dec 9, 1991: MV, Document created Sep 19, 1994: MV, Rectangular beam implemented Jul 7, 1997: MV, Cross implemented Sep 30, 1997: MV, Completely rewritten 'pgbeam'.