random color -c flag broken in d.vect

[cmbarton]

d.vect -c no longer colors vector areas in random colors. I just tried it on the geology map from the spm07 demo set (after rebuilding the map for GRASS 7). All areas remain displayed as grey. I tried it from the wxGUI and from the command line using d.mon. There were no errors It just didn't work.

[cmbarton]

A followup. This works fine on GRASS 6.4.2 svn

[cmbarton]

This is caused by setting the layer default to -1 instead of 1. Setting this default to -1 causes other problems with querying and labeling. IMHO, the default should be 1, which is the case for most vectors and would avoid bogus errors like this one.

Michael

[neteler]

Replying to cmbarton:

This is caused by setting the layer default to -1 instead of 1. Setting this default to -1 causes other problems with querying and labeling. IMHO, the default should be 1, which is the case for most vectors and would avoid bogus errors like this one.

I wonder where the new -1 default in GRASS 7 is documented. Not in

​http://grass.osgeo.org/wiki/GRASS_7_ideas_collection ​http://trac.osgeo.org/grass/wiki/Grass7/VectorLib ​http://trac.osgeo.org/grass/wiki/Grass7/NewFeatures#Libvector ?

[cmbarton]

This seems to be a global default chosen throughout all vector modules that have the option of choosing layers. Where is it set for all of GRASS 7 vectors?

Michael

[martinl]

Replying to cmbarton:

This seems to be a global default chosen throughout all vector modules that have the option of choosing layers. Where is it set for all of GRASS 7 vectors?

it's G_OPT_V_FIELD_ALL defined in gislib source:grass/trunk/lib/gis/parser_standard_options.c#L468​

Regarding d.vect we could use for layer option G_OPT_V_FIELD which defines default answer as 1. Then layers different from '1' will be not rendered by default. Or we could just fix d.vect to colorize vector features based on layer '1' when layer=-1 is entered.

[cmbarton]

It also affects querying and labels for d.vect. Additionally, it looks like -1 is the default layer selected for all other v.* modules. This may or may not cause problems. I understand your point.

But the most common case for vectors is to have one layer. Someone who wants to display more than one layer can switch to -1 for display as easily as someone who wants to use layer 1 instead of -1. But it seems we should default to the most common case rather than less common ones.

Michael

[wenzeslaus]

d.vect -c map=geology works as expected.

d.vect --help now says:

layer   Layer number or name ('-1' for all layers)
         A single vector map can be connected to multiple database tables. This number determines which table to use. When used with direct OGR access this is the layer name.
        default: 1

Most of the modules now (7.0) use G_OPT_V_FIELD which has layer name/number 1. Several modules use G_OPT_V_FIELD_ALL which uses -1 as default.

Closing as fixed.