Gtopo - keyboard use.

Especially on a laptop, I appreciate being able to use gtopo without having to use a mouse or pointing device, and it can be quite handy to use the keyboard in any case. Here is how you do it:

Page UP zooms out (changes to a larger scale map series).
Page DOWN zooms in (changes to a smaller scale map series).
Arrow keys move left, right, up, and down in increments of 1/4 of the vieweing area.

These six keys are sufficient to allow you to roam around and change scale.
Two other keys trigger special features:

Pressing the S key (upper or lower case) dumps a snapsnot of the current area being viewed to the file gtopo.jpg in the current directory. This will fail if the current directory is not writeable by the user running gtopo. Notice that this same filename gets overwritten each time you do this, so you will need to copy or rename the file to avoid this. Emitting a .jpg file can be handy in and of itself, but what I usually then do is to convert this to a postscript file and print it via:

convert gtopo.jpg mymap.ps
lpr mymap.ps

When I use the standard viewport setting of 640 by 800 pixels, this prints quite nicely on 8.5 by 11 inch paper, at a somewhat indeterminate scale. If you are using A4 paper (or something else), you will need to experiment.

Pressing the I key (upper or lower case) pops up an "information" window that shows the current latitude and longitude, and also allows target coordinates to be entered. When coordinates are entered and the "go" button is pushed, the map center moves to the selected position (if accessible).

Feedback? Questions? Drop me a line!

Gtopo / tom@mmto.org