function d2r, degs, arcsec=arcsec
 ;+
 ; NAME:
 ;     d2r
 ;
 ; PURPOSE:
 ;     convert degrees to radians using the fewest characters
 ;     typed on the command line. this function is for lazy
 ;     typists.
 ;
 ; INPUTS:
 ;     degs - angle in degrees (or in arcseconds if /arcsec).
 ;
 ; KEYWORDS:
 ;     arcsec - set if input angle is in arcseconds.
 ;
 ; OUTPUTS:
 ;     the angle in radians. output type is always double.
 ;
 ; EXAMPLE:
 ;     angle = d2r(0.151, /arcsec)
 ;
 ; MODIFICATION HISTORY:
 ;     written 2005-11-11 by mikewong
 ;-

return, !dpi/180d * (keyword_set(arcsec) ? degs / 3600d : degs)
end