[R-sig-Geo] get() in raster ?
Agustin Lobo
alobolistas at gmail.com
Mon Nov 22 23:39:47 CET 2010
Works for stack and not for brick:
> inMemory(N1)
[1] FALSE
> v <- list(N1, N2, N3)
> do.call(stack, v)
class : RasterStack
nlayers : 3
nrow : 1905
ncol : 3697
ncell : 7042785
projection : +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs +towgs84=0,0,0
min value : 0 0 0
max value : 255 255 255
extent : -80.00446, -46.99554, -13.00446, 4.004464 (xmin, xmax,
ymin, ymax)
resolution : 0.008928571, 0.008928571 (x, y)
> do.call(brick, v)
Error in as.matrix(getValues(r)) :
error in evaluating the argument 'x' in selecting a method for
function 'as.matrix'
Calls: do.call ... <Anonymous> -> addLayer -> addLayer -> .local -> as.matrix
> bn = do.call(stack, v)
> b <- brick(bn)
Error in .readRasterLayerValues(x, 1, x at nrows) :
could not find function "GDAL.open"
Calls: brick ... getValues -> getValues -> .local -> .readRasterLayerValues
Agus
2010/11/22 Robert J. Hijmans <r.hijmans at gmail.com>:
> Hi Agus,
>
> This is somewhat puzzling. The general approach works in this example:
>
> r1 <- raster(nrow=10, ncol=10)
> r1[] <- 1
> r3 <- r2 <- r1
> v <- list(r1, r2, r3)
> do.call(stack, v)
>
> # or simply:
> s <- stack(v)
>
> # or the more convoluted, if you have the object names rather than the
> objects themselves:
> v <- list(get("r1"), get("r2"), get("r3"))
> s <- stack(v)
>
> #And finally, if you want a brick (as you are dealing with large
> files, I think it is more efficient to first make a stack and then
> write the results to a brick):
>
> b <- brick(s)
>
> # Although in my example, this does also work:
> b <- do.call(brick, v)
>
>
>
> On Sun, Nov 21, 2010 at 10:22 AM, Agustin Lobo <alobolistas at gmail.com> wrote:
>> Thanks Edzer, but neither work:
>>> v = list("r1","r2","r3")
>>> do.call(brick, v)
>> Error in .rasterObjectFromFile(x, objecttype = "RasterBrick", ...) :
>> file: r1 does not exist
>> Calls: do.call ... <Anonymous> -> <Anonymous> -> .local -> .rasterObjectFromFile
>
> Makes sense, because you are using character arguments, which are
> interpreted as filenames.
>
>>> v = list(r1, r2, r3)
>>> bN = do.call(brick, v)
>> Error in .rasterObjectFromFile(x, objecttype = "RasterBrick", ...) :
>> file: r1r2r3 does not exist
>
> Strange to have r1r2r3 concatenated.
>
>> Calls: do.call ... <Anonymous> -> <Anonymous> -> .local -> .rasterObjectFromFile
>> In addition: Warning messages:
>> 1: In if (x == "" | x == ".") { :
>> the condition has length > 1 and only the first element will be used
>> 2: In if (fileext %in% c(".GRD", ".GRI")) { :
>> the condition has length > 1 and only the first element will be used
>> 3: In if (!file.exists(x)) { :
>> the condition has length > 1 and only the first element will be used
>> 4: In if (file.exists(grdfile) & file.exists(grifile)) { :
>> the condition has length > 1 and only the first element will be used
>>
>> Also, in the real case the raster objects (i.e.,N1, N2 and N3) will
>> not have values in memory, so I'm not
>> positive that the list would be the way to go:
>>
>
> Should not matter
>
>>> class(N1)
>> [1] "RasterLayer"
>> attr(,"package")
>> [1] "raster"
>>
>>> inMemory(N1)
>> [1] FALSE
>>
>>> v = list(N1, N2, N3)
>>> bN = do.call(brick, v)
>> Error in as.matrix(getValues(r)) :
>> error in evaluating the argument 'x' in selecting a method for
>> function 'as.matrix'
>> Calls: do.call ... <Anonymous> -> addLayer -> addLayer -> .local -> as.matrix
>
> This may be a real bug. But perhaps you can do
> sN = brick( do.call(stack, v) )
>
>>
>> By now I'm editing the output of
>> paste("N",1:360,sep="")
>> for a call to brick() including the 360 raster objects. But there has
>> to be an elegant way of doing this. Not a critical issue though.
>>
>> Agus
>>
>> 2010/11/20 Edzer Pebesma <edzer.pebesma at uni-muenster.de>:
>>> Just pushed "send" too fast -- try without quotes to pass the objects
>>> instead of their names:
>>>
>>> v = list(r1, r2, r3)
>>> do.call(brick, v)
>>>
>>>
>>> On 11/20/2010 11:51 AM, Agustin Lobo wrote:
>>>> ok, the problem is that, as noted by Carson,
>>>> I must use get("v") and not get(v).
>>>>
>>>> But still have problems to use get() within stack() or brick():
>>>>> r1 = raster(SM[,,1])
>>>>> r2 = raster(SM[,,2])
>>>>> r3 = raster(SM[,,3])
>>>>> v = c("r1","r2","r3")
>>>>> get("v")
>>>> [1] "r1" "r2" "r3"
>>>>> bSM = brick(get(v))
>>>> Error in .rasterObjectFromFile(x, objecttype = "RasterBrick", ...) :
>>>> file: r1r2r3 does not exist
>>>> Calls: brick -> brick -> .local -> .rasterObjectFromFile
>>>>
>>>> ( I'm trying to use get() because have to
>>>> create a brick with 360 files that have been read as raster objects within
>>>> a loop using assign() )
>>>>
>>>> Agus
>>>>
>>>>
>>>> 2010/11/19 Robert J. Hijmans <r.hijmans at gmail.com>:
>>>>> This suggest that you have an object "r1" that is a Raster* object.
>>>>> Perhaps because of a saved session?
>>>>> Have you looked at
>>>>> ls()
>>>>> Robert
>>>>>
>>>>> On Fri, Nov 19, 2010 at 1:24 PM, Agustin Lobo <alobolistas at gmail.com> wrote:
>>>>>> Hi again!
>>>>>>
>>>>>> I'm having problems because cannot use get() from base once package
>>>>>> raster has been installed:
>>>>>>
>>>>>>> v = c("r1","r2","r3")
>>>>>>> v
>>>>>> [1] "r1" "r2" "r3"
>>>>>>> get(v)
>>>>>> Loading required package: raster
>>>>>> Loading required package: sp
>>>>>> raster version 1.6-22 (17-November-2010)
>>>>>> class : RasterLayer
>>>>>> nrow : 18
>>>>>> ncol : 36
>>>>>> ncell : 648
>>>>>> projection : +proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0
>>>>>> xmin : -180
>>>>>> xmax : 180
>>>>>> ymin : -90
>>>>>> ymax : 90
>>>>>> xres : 10
>>>>>> yres : 10
>>>>>>
>>>>>> Even not having loaded raster, it gets automatically loaded once I
>>>>>> call get(). Is this a bug?
>>>>>> In general, is there a way to force that, in case of conflict, you run
>>>>>> a particular function from a given package?
>>>>>>
>>>>>> Thanks!
>>>>>>
>>>>>> Agus
>>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> R-sig-Geo mailing list
>>>>> R-sig-Geo at stat.math.ethz.ch
>>>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>>>>
>>>>
>>>> _______________________________________________
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>>>
>>> --
>>> Edzer Pebesma
>>> Institute for Geoinformatics (ifgi), University of Münster
>>> Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
>>> 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de
>>> http://www.52north.org/geostatistics e.pebesma at wwu.de
>>>
>>> _______________________________________________
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>>> R-sig-Geo at stat.math.ethz.ch
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>>
>>
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