Function: PGBEAM
Purpose: Draw elliptical shaded beam (PGPLOT)
Category: PLOTTING
File: pgbeam.c
Author: M. Vogelaar
Use: CALL PGBEAM( XCENTRE, Input real
YCENTRE, Input real
MAJOR, Input real
MINOR, Input real
PA, Input real
DELTA, Input real
SLOPE Input real
SHAPE ) Input integer
XCENTRE X position of centre of ellipse in
world coordinates.
YCENTRE Same for Y position
MAJOR Major axis of ellipse
MINOR Minor axis of ellipse
PA Position angle of ellipse wrt. pos x-axis
in degrees.
DELTA Separation shading lines in world
coordinates.
SLOPE Slope of shading lines in degrees.
SHAPE 1: Plot shaded ellipse
2: Plot shaded rectangle (e.g.IRAS beam)
3: Plot cross
Description: Draw an elliptical beam with specifications (origin and axes)
in world coordinates. The position angle of the major
axis is wrt. the pos. x-axis. The ellipse is rotated
counter-clockwise. If user wants shading (line pattern
only) you can give the slope of the lines in 'SLOPE'
and the distance between the lines in world coordinates
'DELTA' in the y-direction in an unrotated frame.
However, lines are plotted in the rotated frame.
Updates: Dec 9, 1991: MV, Document created
Sep 19, 1994: MV, Rectangular beam implemented
Jul 7, 1997: MV, Cross implemented