[GRASSLIST:8569] Re: Changing scale of raster map

[Ian MacMillan]

Bruno, first thing, in a latlong projection, the units of resolution 
are given in degrees.  So ewres=1 means that your cell width is one 
degree.  Most other projections have a cell unit of meters.  For 
example an ewres=1 in an UTM projection would mean that your cell width 
is one meter.  To change your resolution, you can use

g.region res=your_res

for example

g.region res=00:00:30 yields a 30 arc second resolution in a latlong 
projection.

Hope this helps,
Ian


On Oct 10, 2005, at 7:35 AM, Bruno GUILLAUME wrote:

> Dear GRASS users,
>
> My problem concerns a raster in lat-lon projection, having a given 
> resolution of ewres1,nsres1. For every cell, the category value is 
> expressed in kilogram.
> I need to transform it into  the same grid but with coarser 
> resolution, say ewres2=10*ewres1 and nsres2=10*nsres1, BUT the 
> transformation need to be mass-conservative (so, I need to get exactly 
> the same amount in kilograms with finer and coarser resolution).
>
> Can I do in a simple way with GRASS ?
>
> Thanks in advance,
>
> Bruno Guillaume.
>
>
 >
 >
What happens if a big asteroid hits Earth? Judging from realistic 
simulations involving a sledge hammer and a common laboratory frog, we 
can assume it will be pretty bad.
  - Dave Barry


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