[GRASS-user] Floating point histogram x-axis display

[Markus Neteler]

On Fri, Dec 28, 2012 at 6:39 AM, RichardC <richtcooper at hotmail.com> wrote:
> Hi,
>
> I notice with a floating point raster that there appears to be a numbering
> problem in the histogram's x-axis.
>
> All values in the file are are from zero to 159, no negative values.
> Horizontally expanding the histogram is not helpful re the x values. Please
> see attached file.

Yes, the d.histogram ticks calculation is far from satisfying.
(see below)

> Could Gnuplot be a convenient workaround - if you could point me to any up
> to date and relevant literature?

Gnuplot may be a way, see i.spectral for a usage (it is a script).

The problem has been addressed in GRASS7:

http://grass.osgeo.org/screenshots/user-interface/
--> currently 4th screenshot:
      Logarithmic histogram of a population map. The axes are fully customizable

I don't expect that the old d.histogram will gain a better axes support
but perhaps we find a volunteer to improve it?

Markus