Question on histograms from Raster and RasterVIS packages
Nuno,
I thought you might say that. I have used R with GRASS GIS, which
interfaces using the spgrass6 contributed package. I have analyzed some
pretty large GIS raster files, looking at radar precipitation data, and the
approach I suggested works well. The data imported into R using sp (the
basis for spgrass6) is an sp raster object. So, from the spgrass6 manual:
After loading R from the GRASS GIS terminal prompt, for example,
spear <- readRAST6(c("geology", "elevation.dem"), cat=c(TRUE, FALSE))
Try looking at this:
summary(spear)
you can do this:
boxplot(spear$elevation.dem ~ spear$geology)
or this, for instance :
hist(spear$elevation.dem)
meanx<-mean(spear$elevation.dem)
abline(v=meanx, col="red")
But, maybe I don't understand the problem??
Regards,
Tom
On Tue, Nov 18, 2014 at 11:21 AM, Nuno S? <nunocesardesa at gmail.com> wrote:
Hey Thomas! Yes thanks, I know it works for the normal hist function which uses 3% of all data (mind I am talking about rasters) which I am not sure that is a good enough sample, I leave that question in the air The problem is it does not work in rasterVIS (which does use all the raster). The error it gives me is the following:
abline(v=m.rst,col="blue",lwd=2)
Error in int_abline(a = a, b = b, h = h, v = v, untf = untf, ...) : plot.new has not been called yet Regards!! Thank you once again! Nuno On 18 November 2014 18:04, Thomas Adams <tea3rd at gmail.com> wrote:
Nuno, This works for me:
require(stats) set.seed(14) x <- rchisq(100, df = 4) hist(x) meanx<-mean(x) meanx
[1] 3.734162
abline(v=meanx, col="red")
Cheers! Tom On Tue, Nov 18, 2014 at 10:56 AM, Nuno S? <nunocesardesa at gmail.com> wrote:
Hello!
My aim is to add a "Median" or a "Mean" line to an histogram plot in R.
The problem is the following:
The "hist" function from the raster package uses a maximum of 100 000
values for generating the histogram but allows me to edit the plot, so I
can easily add a line within the plot using abline.
The "histogram" function in rasterVIS uses all my dataset but does not
allow editing of the plot area, so I cannot use the abline function to
add
this line (or I do not know how to do it).
If you have an alternative or a solution to work around this, I am all
hears
Thank you for any help in advance!
Ciao!
--
Nuno C?sar de S?
+351 91 961 90 37
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