Hi All,
Changing the data type to INT4U worked for my application (14400 rows and
19200 columns).
Thank you all for your help!
On Tue, Apr 30, 2013 at 1:30 PM, Robert J. Hijmans wrote:
> This is indeed because of precision loss due to FLT4S. Numbers larger
> than 16777216 cannot be recovered t
This is indeed because of precision loss due to FLT4S. Numbers larger
than 16777216 cannot be recovered to the exact integer from a 4 byte
floating point file. To avoid this I will change the default that
'raster' uses to FLT8S. This will double file sizes if the default is
used.
Ted, you can achi
Hi Tom
In fact there is a difference:
see ?dataType why I do not use 'INT4U'. Probably the reason is that writeStart
(see ?writeRaster) uses FLT4S as default and adding values in blocks the
function doesn't know that FLT4S is not enough where else with out[] <-
1:ncell(out) it knows! I think t
Ted & Matteo--
Is this perhaps a dataType problem? I don't recall the specifics of the
significand of FLT4S but it's roughly 8 digits, so 3800 may exceed it.
You might try changing the dataType to INT4U to see if the dataType is the
problem.
Tom 2
On Tue, Apr 30, 2013 at 7:22 AM, Matteo M
Ted you are right!
I have tried a few things and I can not explain the behaviour.
@Robert may the example below helps a little further.
I have also tried to write into a tif and an img file but it doesn't change.
Also after reloading the file out <- raster("tmp.grd") the problem persists.
Start
Dear Matteo,
Thanks for your response.
You approach would work except that my computer can't handle it well since
it loads everything into memory. That is why I used the more complicated
approach outlined here (
http://cran.r-project.org/web/packages/raster/vignettes/functions.pdf).
On Tue
Dear Ted,
Isn't it simply that?
out <- raster(nrow=2,ncol=1900)#modisRasterAll
out[] <- 1:ncell(out)
tail(out)
>>> Ted Rosenbaum 04/29/13 11:28 PM >>>
Hi,
I am trying to assign a unique ID number to each tile in a large raster
file.
My code is below:
##Write tile indexed MODIS file
Hi,
I am trying to assign a unique ID number to each tile in a large raster
file.
My code is below:
##Write tile indexed MODIS file
#Prelims
nColVal<-190
outFileName <- 'tmp.grd'
#Set up raster
out <- raster(nrow=2,ncol=nColVal)#modisRasterAll
##Get number of colums and blocksize
outCol <-
