Hi Peter,
I am not sure which plot function you are using, but I did something
similar where I plotted a series of maps for crop yields with a
constant scale for yield, using sp.plot. My data were in an attribute
table linked to a polygon, whereas yours are grids, but maybe
something in the following can be used?
# Loop through columns of shapefile (eval.shp2) to plot: Yield from
various cultivars
for (i in 4:13) {
print(paste("Plotting column: ", i)) # Column counter
# Establish scale limits and title vector
scmax <- round(max(eval.s...@data[, 4:12]) / 100, 0) * 100 #
Set max scale value
scmin <- round(min(eval.s...@data[, 4:12]) / 100, 0) * 100 #
Set min scale value
byval <- 25
titlevec <- paste("district maize yields (kg/ha) 1981-99:
Cultivar", culnames[i - 3])
# Spplot
print(spplot(eval.shp2[-c(22,69),], z = i,
sp.layout = list(sa.lst),
col.regions = topo.colors(500),
at = seq(scmin, scmax, by = byval), main = titlevec))
}
In your case, since you are using grids, maybe you can read the
interpolated grids' metadata first to extract the max and min and
values for setting your scale. Or perhaps you know in advance what
the max and min should be, and can simply enter those values?
Hope this is somewhat useful.
Cheers, Lyndon
On Thu, Oct 28, 2010 at 3:12 PM, Peter Larson <pslars...@gmail.com> wrote:
> Hello!
>
> I have a problem.
>
> I am using IDW to interpolate a daily series of geospatial
> observations. Thus, I want to produce a large number of sequential
> maps.
>
> I want them to all represent the same color scale. Is there any way to
> fix the color scale so that it is the same for all the plots?
>
> Thanks,
>
> Pete
>
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--
Lyndon Estes
Research Associate
Woodrow Wilson School
Princeton University
+1-609-258-2392 (o)
+1-609-258-6082 (f)
+1-202-431-0496 (m)
les...@princeton.edu
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