[GRASS-dev] r.cva output file missing

[Rebecca Mayer]

By going through the r.cva options I finally figured
out the key to doing 'sites' analysis without
triggering a segfault: use the -i flag. This flag
seems to tell r.cva to ignore fields in the vector map
that may define the parameters spot, offseta, offsetb,
azimuth1, azimuth2, vert1, vert2, radius1, and
radius2. (My sites map did not have fields with these
parameters.)

Example of what worked:
---------------------------------------
GRASS 6.2.2 (Lambert):~ > r.cva -f -i
input=sle_demp_5pt sites=sle_unc3_1pt
output=sle_view18 obs_elev=0 target_elev=0
max_dist=2000 type=sites 

 100%
Creating raster map 'sle_view18' 
Writing raster map 'sle_view18': 
 100%

Sample: requested =  0.00004%  attempted =  0.00004% 
actual =  0.00004%

Creating support files 
Job finished
---------------------------------------

The parameters spot, offseta, etc. when entered in the
r.cva command work as global settings, but I still got
a segfault unless -i was also used.

e.g.:
---------------------------------------
GRASS 6.2.2 (Lambert):~ > r.cva -f -h
input=sle_demp_5pt sites=sle_unc3_1pt
output=sle_view20 max_dist=2000 type=sites spot=0
offseta=0 offsetb=0 azimuth1=0 azimuth2=360 vert1=90
vert2=-90 radius1=100 radius2=1000 curvc=0.0 

 100%
Creating raster map 'sle_view20' 
Writing raster map 'sle_view20': 
 100%
Segmentation fault
---------------------------------------

Thanks for your inputs and suggestions! Without them I
might have given up.

One quick note on an inconsistency I noticed between
the r.cva extension and its documentation: The help
file says "The range is -90 to 0 for 'VERT1' and 0 to
90 for 'VERT2'" whereas the r.cva dialog window sets a
range of 0 to 90 for VERT1 and -90 to 0 for VERT2.
Don't know if this affects the calculations.