Question on histograms from Raster and RasterVIS packages
Hello! Yes, it sorted the problem but maybe not as we were expecting, you've "liberated" me from the raster package 3% data limitation and now I can work with it easily as a normal histogram. Basically the trick that I got from the "readRAST6" function you suggested is that it converts it into sp objects (SpatialGridDataFrame in this case i guess). From here it is easy: all I need is to convert the rasters to an sp object and from there I am back working with normal hist functions. So, using the conversion: as(inputraster,"SpatialGridDataFrame") sorted it out. The rest is history. I hope they update this method into the raster package because there is no need to be limited to a 100 000 sample which is usually kind of low for RS data. Found a similar limitation on usdm package recently which chooses to needlessly convert a whole raster into a data.frame before calculating VIF between variables. For huge rasters, it would kill off the computer memory. Because of that, I guess the authors also made a limit on the sample size (which was not what was actually killing the computer memory) Dr Greg Yes, I think the rasterVIS package uses grid. maybe it can be inserted when we call the histogram function, but making it do a vertical line might be kind of complicated, I think just from looking to how it is called. Thank you guys for the suggestions!! I jump between them also, but making graphs is usually easy enough just using R. anyway, it is so great to have all these awesome languages and softwares linked together. Best of luck for all! Nuno
On 18 November 2014 18:38, Thomas Adams <tea3rd at gmail.com> wrote:
Nuno, Possibly having a reproducible example would help. I do all my spatial analysis work starting from GRASS GIS and calling R from the GRASS prompt ? this works very well. Tom On Tue, Nov 18, 2014 at 11:35 AM, Greg Snow <538280 at gmail.com> wrote:
Nuno, Does rasterVIS use base or grid graphics? The place I usually see the error that plot.new has not been called yet is when trying to use a base graphics function to augment a plot created using grid graphics. I suspect that the plot created used grid graphics and that is why abline is not working for you. There is a 'grid.abline' function in the grid package, though it does not look like it would work easily for a vertical line, so you may need to dive into the details of using grid in more detail, probably using the grid.lines function. There is also the gridBase package which helps grid and base graphics play nicely together, though it could be a bit of overkill for just adding a vertical line. 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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Nuno C?sar de S?
+351 91 961 90 37
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-- Gregory (Greg) L. Snow Ph.D. 538280 at gmail.com
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