[GRASS-user] importing gridded xyz data with titled grid

[Hamish]

Julian Burgos wrote:
> Sorry if this is a basic question...I´m taking my fist
> steps with GIS/GRASS.
> I have a relatively large dataset (~250000 rows) consisting
> of lat, long and a data value.  The data has been
> collected in a regular grid, but the grid is "tilted". 
> In other words, along a row the latitude values increase
> constantly, and along a column the longitude values do the
> same.  I need to to convert this data to a raster
> file.  I have no information on the native projection
> of the data.
> Any ideas/tips/suggestions on how to tackle this?

r.in.xyz

run it first to scan & find the bounds (If you don't know
already)

run g.region to set the region bounds and resolution, as needed

run r.in.xyz with method=n, then run r.univar on the output
to ensure that every cell has just one value in it (input grid =
output grid)

finally, when you are convinced that you have the grids lined up
correctly run r.in.xyz with method=mean (or at this point min
or max, should all be the same if n is always = 1)


> I have a large dataset

no problem at all.


Hamish