[GRASS-dev] v.to.rast with category label support

[Michael Barton]

Helena and others,

The current v.to.rast syntax dates from the days of the old vector
architecture, with some tweaking to allow it to use layers and attribute
columns in the current architecture.

IMHO, what would make more sense now is to have the following syntax:

V.to.rast input=name output=name [cat=cat, column-name, auto] [label=cat,
column-name] [layer=integer] [color=column-name, auto]... With various flags
and defaults like we have now.

"cat" would use the vector cat field to populate the cat or label field in
the raster. This would be the default for the "cat=" option.

"auto" would automatically generate a series of integers 1...n to populate
the raster cat field.

The raster label would have no default value, though the user could set it
to the vector cat or any other column.

The color= option would allow a user to specify a vector color column
(originally GRASS_RGB) that contains color info (GRASS named colors or
RRR:GGG:BBB) that would be used to create a color table for the resulting
raster. "color=auto" would simply generate a color table automatically as is
the case now and would be the default for this optoin.

What do you think?

Michael


On 1/21/07 12:51 PM, "Helena Mitasova" <hmitaso at unity.ncsu.edu> wrote:

> While working on a replacement data set for spearfish
> I found that when we convert from vector data to raster there is no
> option to add labels
> so it needs to be done manually after the conversion.
> But there is only r.support to do that and it would be hard to use if
> you have
> large number of categories and it is practically unusable if the
> category numbers are large (e.g. I have only 5 zipcodes ranging from
> 27511 - 27606
> and r.support wants me to start with category 1).
> 
> I rarely have to use this for my research work and if it is needed
> I just edit the cat file, but that is not a good solution.
> 
> currently we have:
> v.to.rast input=name output=name [use=string] [column=name]
> [layer=integer] [value=float]
> 
> would it be possible to add
> uselabel= with options at least: attr,cat, although some people may
> find the others useful: val,z,dir
> column= this one does not have to be numeric for labels
> 
> Or is there any other way how to handle the raster map cat labels
> that I am missing?
> 
> Helena
> 
> P.S. Markus, Brad I am posting this to the list as it involves vector
> data conversion
> rather than just import.
> 
> 
> Helena Mitasova
> Dept. of Marine, Earth and Atm. Sciences
> 1125 Jordan Hall, NCSU Box 8208,
> Raleigh NC 27695
> http://skagit.meas.ncsu.edu/~helena/
> 
> 
> 
> 
> 

__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton