grid[/qual] [dalpha] [ddelta]
Draw a grid of sky coordinates over the currently displayed image. The default will plot a preassigned grid spacing. This can be changed by specifying dalpha and ddelta in degrees.
Draw a the grid in galactic coordinates.
Specify the color to be used for the grid. The default is white.
This will plot only tick marks on the frame of the image, corresponding to preassigned spacing in dalpha and ddelta. If not specified a full grid across the image is plotted.
Example:
grid ! draw a grid with the default steps in
! in celestial coordinates
grid 0.5 0.5 ! draw a grid in 0.5 deg ra and dec steps
grid/gal ! draw a grid in galactic coordinates