IGREY-Produces a grey-scale plot of an image

Description:

Plots an image using a monochrome display look-up table.

Parameters:

IMAGE

Name of image to be grey-scaled.

YSTART

First Y value to be displayed.

YEND

Last Y value to be displayed.

XSTART

First X value to be displayed.

XEND

Last X value to be displayed.

LOW

Lowest data level used (black level).

HIGH

Highest data level used (white level).

LABEL

Label for plot.

ADJUST

Adjust scales so as to fill display?

HARDCOPY

Generate a hardcopy plot?

See also:

FIGARO: IMAGE.
KAPPA: DISPLAY, GREYPLOT.

Source comments:

 I C O N T    /    I G R E Y

 Handles an 'ICONT' command, producing a contour plot of an
 image on either the current hard or soft graphics device,
 or an 'IGREY' command, which produces a grey-scale plot.

 Command parameters -

 IMAGE    (Character) The name of the image to be contoured.
 YSTART   (Numeric) The first Y value to be displayed.
 YEND     (Numeric) The last Y value to be displayed.
 XSTART   (Numeric) The first X value to be displayed.
 XEND     (Numeric) The last X value to be displayed.
          Note that this initial version only accepts these
          values as pixel numbers.
 LOW      (Numeric) The minimum contour level (ICONT) or
          the black level (IGREY).
 HIGH     (Numeric) The maximum contour level (ICONT) or
          the white level (IGREY).
 CONTOURS (Numeric) The number of contours displayed - these
          will be divided evenly between HIGH and LOW, unless
          explicitly specified as BYVALUE. (ICONT only).
 LABEL    (Character) A label for the plot.
 THICKNESS(Numeric) Thickness to use for lines (only used if
          the HARDCOPY parameter is specified, and ICONT only)
 LEVELS   (Numeric array) The contour levels to use (ICONT only,
          and only if the BYVALUE keyword is specified).

 Command keywords -

 HARDCOPY Output the plot to the current hard graphics device.
 ADJUST   Adjust scales so as to fill screen.
 BYVALUE  For ICONT, indicates that explicit contour values are
          specified in the LEVELS parameter.

 User variables used -   (">" input, "<" output)

 (>) SOFT     Current device/type (PGPLOT convention) for soft
              graphics output.
 (>) HARD     Current device/type (PGPLOT convention) for hardcopy
              graphics output.
 (<) TVXST    is set to the starting x-value for the plot.
 (<) TVXEN    Is set to the final x-value for the plot.
 (<) TVYST    is set to the starting y-value for the plot
 (<) TVYEN    is set to the final y-value for the plot.
 (<) TVHIGH   Is set to the same value as HIGH.
 (<) TVLOW    Is set to the same value as LOW.
 (<) PGENVARG Arguments used for PGENV.
 (<) IMFILE   File containing the displayed image.

                                           KS / CIT 21st March 1984.