[GRASSLIST:9232] mapping the output of a population model

[Luigi Ponti]

Thanks Stephan,

I was able to import the ASCII text file to vector points and interpolate between them.
Also, based on a very useful but unrelated discussion, I obtained a very pretty shaded relief over which I draped the interpolated raster.

Now I have started clipping the region that are not of interest to the analysis. To clip out what is not California, I have transformed a vector layout of the state to a raster via v.to.rast, and used it as a mask in v.surf.rst.

How could I clip regions that have an elevation greater than a particular value based on the elevation model raster?

Thanks again,

Luigi





Stephan Holl wrote:

>Hello Luigi, 
>
>On Mon, 21 Nov 2005 17:20:05 -0800 Luigi Ponti <lponti at infinito.it>
>wrote:
>
>  
>
>>Thanks Ian and Hamish,
>>
>>I was eventually able to fix the problem by downloading a unprojected 
>>California layout shapefile (form <www.census.gov>) and then
>>importing it via v.proj in the location with the digital elevation
>>map. Apparently the official shapefile of California layout has a
>>wrong latitude.
>>
>>Next step is to connect the output table of the population model 
>>(population densities at weather stations) to the map I have just 
>>created. This would hopefully result in an interpolated raster.
>>
>>Hamish suggested the following:
>>
>>Load in site data with v.in.ascii & interpolate between sites with
>>v.surf.rst.
>>
>>According to the manual v.in.ascii uses the | separator. Is it worth
>>to manually put the file in that format or do you think is better to
>>convert it in a database to connect with a specific command?
>>
>>    
>>
>
>you could use the fs="," for selecting a , as a selector.
>
>have a look at the manual-page of v.in.ascii.
>
>g.manual v.in.ascii or
>
>v.in.ascii -h
>
>
>Best
>	Stephan
>
>
>
>  
>