[GRASS-dev] r.cva output file missing

[benjamin.ducke at ufg.uni-kiel.de]

Rebecca Mayer wrote:
>> What is the size and x-y resolution of your mapset?
>
> nsres:      86.08807728
> ewres:      86.08807728
> rows:       3793
> cols:       3719
> cells:      14106167
>
>> Try adjusting the cell sizes so that you have
>> integer cell extents.
>
> r.cva works in this mapset when set to 'random' but
> not 'sites' type of analysis. Would the cell extents
> still be the problem?

Yes, but only if you are running this on Windows.

>
> Below are the terminal outputs for three runs using
> the same the dem file. In the first run I used a
> binary raster map to define 1 viewpoint for a 'sites'
> analysis and got a segfault. In the second run I used
> a vector map to define 1 viewpoint for a 'sites'
> analysis and got a segfault. The third run was set to
> 'random' with a sample frequency designed to produce
> one viewpoint. This run completed successfully.
>
> Terminal output:
> -----------------------------------------------------
> GRASS 6.2.2 (Lambert):~ > r.cva -f input=sle_demp_5pt
> viewpt_mask=sle_unc3_1pt output=sle_view13 obs_elev=60
> target_elev=1.6 max_dist=2000 type=sites curvc=0.13
>
> Segmentation fault

This one crashes because you are using an unsupported combination
of options. Type=sites *must* be used in conjunction with an
input vector map of site location(s). This is really a bug in
the r.cva options parser. Instead of crashing, it should show
an appropriate error message.

> GRASS 6.2.2 (Lambert):~ > r.cva -f input=sle_demp_5pt
> sites=sle_unc3_1pt output=sle_view14 obs_elev=60
> target_elev=1.6 max_dist=2000 type=sites curvc=0.13
>
>  100%
> Creating raster map 'sle_view14'
> Writing raster map 'sle_view14':
>  100%
>
>
> Sample: requested = 10.00000%  attempted =  0.00001%
> actual =  0.00001%
>
> Creating support files WARNING: unable to find
> [sle_view14] in [viewtest]
> WARNING: category support for [sle_view14] in mapset
> [viewtest] missing
> Segmentation fault

This one looks strange. The calculations actually do finish
correctly but writing the final output map fails for some reason.

Try dropping all options except for type=sites and sites=<vectmap>
and work your way from there.

Careful with option "curvc". It is basically untested and
nobody ever checked whether it gives sane results.

Which version of r.cva are you using?

Where did you download it?

Benjamin

> GRASS 6.2.2 (Lambert):~ > r.cva -f input=sle_demp_5pt
> output=sle_view151 obs_elev=60 target_elev=1.6
> max_dist=2000 seed=1 sample=.00001 type=random
> curvc=0.13
>
> Creating raster map 'sle_view151'
> Percentage complete:
>  100%
>
> Writing raster map 'sle_view151':
>  100%
>
>
> Sample: requested =  0.00001%  attempted =  0.00001%
> actual =  0.00001%
>
> Creating support files
> Job finished
> ----------------------------------------------------
>
>
>
>

-- 
Benjamin Ducke
Senior Applications Support and Development Officer

Oxford Archaeological Unit Limited
Janus House
Osney Mead
OX2 0ES
Oxford, U.K.

Tel.: ++44 (0)1865 263 800
benjamin.ducke at oxfordarch.co.uk