AIPS HELP file for DARKLINE in 31DEC19
As of Tue Dec 11 21:54:16 2018
Type: Adverb (Scalar)
Use: Plot programs are able to draw "dark" as well as "bright"
vectors. The dark ones are normally drawn to provide
contrast when the background grey-scale image is strong.
DARKLINE is used to control the grey level, after scalings
and FUNCTYPE (in the range 0 - 1) at which the switch to
dark is made. The default value is 0.33.
GREYS.......Make a grey-scale plot with contours.
PCNTR.......Make a grey-scale, contour, and polarization vector