GREYSCALE-MAP (also GRAYSCALE-MAP)

Make a greyscale plot of any slice of the spectral data cube. Select the plot axes using SET-MAP-SCALES, while various other features can be turned on or off using SET-MAP-PARAMETERS (q.v.)

The program integrates the intensity over the nominated range of the third ``z-axis'' coordinate (most commonly velocity), and if AVERAGE intensity over the range is selected, then divides by the overall z-axis range to produce an average intensity (otherwise just the integrated total is plotted). If smoothing is selected in SET-MAP-PARAMETERS then the data plane is interpolated onto a finer sampling before plotting, which yields a more aesthetically pleasing image.

If zero sizes are selected in SET-MAP-SIZE then the routine uses the available graphics area to its fullest; if zero limits are selected in SET-MAP-SCALES then the routine plots the entire available data set.

Note that the routine only plots in ``cells'' which have real data. It may be helpful to use INTERPOLATE-MAP to create data entries at unmeasured points so that more of the image plane is greyscaled.

Relevant flags:

LINE_WEIGHT

I4

Default line weight for plotting axes, labels etc.

AUTOGREY

L4

Set greyscale limits automatically from map max and min.

GREYLIM(2)

R4

Levels represented by black (min) and white (max).

COLOUR_TABLE

I4

Number of colour table to use:

1	linear black to white
2	colour contours
3	power-law black to white
4	blue to yellow colours
5	MRAO blue to white spiral

OVERLAY_CONTOURS

L4

Automatically overlay contours on greyscale

PLOT_GREY

L4

Plot greyscale for PLOT-LINE-PAR and CHANNEL-MAPS

Examples:

    >> greyscale<CR>
    Velo range? (km/s  ) [  -3.0000,  13.0000] <CR>
    Integrated intensity? (rather than average) (Y/N) [N] <CR>
    R.A. offset scaled from   80.000 to  -60.000
    Dec. offset scaled from   30.000 to  -30.000
    ..