HELP: sites to raster - attributes
geol1 at CWU.EDU
Thu Jan 26 12:59:28 EST 1995
>We are using grass4.1 trying to convert sites files to raster files.
>Using s.menu we are able to convert the sites into a raster map displaying
>either a 0 or 1 (1 for a site occuring in that cell).
>Our sites files contain an attribute which is snow depth. We want to
>convert the sites file into a raster file, where the raster value is
>the snow depth of the site in that cell (or average of sites in that cell
>if there are more than one). Basically we can't figure it out.
>We are using s.menu with option 7 to create a frequency based raster file,
>but we aren't sure how the categories are determined. Can we define our
>As a side note, can d.colors take an input file instead of needing a
>user to go in for each raster file and manually switch RGB values?
>Thanks for any help..
Use s.menu, as you are doing, but edit the site list so that each site
description begins with a # followed by the numeric value you want
to become the cell value. If even one site is lacking this leading #,
only a binary (0/1) map can be produced.
Option 7 to produce a frequency of occurrence raster map, just counts
the number of sites falling within each cell (size determined by the
current region parameters) and uses the count as the cell value. Setting
a large cell size (say 1000 x 1000 m) can often be of value with this
CWU GIS Lab
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