Graphics Tips & Tricks

When overlaying graphics onto the image display using the IMD kernel, the line width can be controlled via the graphcap 'LO' (line origin) and 'LS' (line slope) parameters, normally defined in the low-level 'imd' entry of the graphcap file. To double the line width and keep the color black then try something like

    imddark|                   :LO#2:LS#2:tc=imdblack:

If you can't modify the system graphcap file then make a private graphcap as follows:

    cl> copy dev$graphcap home$mygraphcap         # copy the file
    cl> edit home$mygraphcap                      # add new entry
    .....add the above line near the top 
    cl> gflush                                    # reinitialize graphics
    cl> display dev$pix 1                         # display and image
    cl> contour dev$pix dev=imddark perim- fill+  # overlay dark contour

Note the line width change will also affect any text being drawn, but this is usually unreadable anyway.

Most postscript hardcopy plots contain a small timestamp message at the corner of the page which some users was to remove. To do this use the -t flag to the SGI translator in the device graphcap entry. For example,

g-lpr|UNIX generic interface to default printer device (lpr):\
    :DD=lpr,tmp$sgk,!{ sgidispatch sgi2uapl -t $F -l$(XO) -w$(XW) \
    -b$(YO) -h$(YW) -p$(PW) | lpr ; rm $F ; }&:tc=sgi_apl:

Use =gcur to start a graphics cursor for tasks (e.g. contour) which don't have one

All cursor mode tasks (or those having a cursor via =gcur) have available a set of upper-case keystrokes. Some favorites are:





X

expand in the x-direction about the vertical cursor position

Y

expand in the y-direction about the horizontal cursor position

Z

expand in x and y about the cross-hair position.

A

relabel the axes if they expand out of view.

T

place a text label at the current cursor position

0

(zero) redraw the screen


See help cursors, or if in the graphics mode, :.help.