[R-sig-Geo] raster: stackApply problems..
Leonidas Liakos
|eon|d@@_||@ko@ @end|ng |rom y@hoo@gr
Tue Nov 26 18:22:19 CET 2019
Why do they seem logical since they do not match?
Check for example index 1 (Sunday). The results are different for the
three processes
> stackapply_mean
class : RasterBrick
dimensions : 300, 300, 90000, 7 (nrow, ncol, ncell, nlayers)
resolution : 500, 500 (x, y)
extent : 0, 150000, 0, 150000 (xmin, xmax, ymin, ymax)
crs : NA
source : /tmp/RtmpkRMXLb/raster/r_tmp_2019-11-26_191359_7710_20324.grd
names : index_5, index_6, index_7, index_1, index_2,
index_3, index_4
min values : 440.0467, 444.9182, 437.1589, 444.6946, 440.2028, 429.6900,
442.7436
max values : 563.8341, 561.7687, 560.4509, 565.8671, 560.1375, 561.7972,
556.2471
> ver_mean
class : RasterStack
dimensions : 300, 300, 90000, 7 (nrow, ncol, ncell, nlayers)
resolution : 500, 500 (x, y)
extent : 0, 150000, 0, 150000 (xmin, xmax, ymin, ymax)
crs : NA
names : layer.1, layer.2, layer.3, layer.4, layer.5,
layer.6, layer.7
min values : 442.7436, 440.0467, 444.9182, 437.1589, 444.6946, 440.2028,
429.6900
max values : 556.2471, 563.8341, 561.7687, 560.4509, 565.8671, 560.1375,
561.7972
> z
class : RasterBrick
dimensions : 300, 300, 90000, 7 (nrow, ncol, ncell, nlayers)
resolution : 500, 500 (x, y)
extent : 0, 150000, 0, 150000 (xmin, xmax, ymin, ymax)
crs : NA
source : /tmp/RtmpkRMXLb/raster/r_tmp_2019-11-26_191439_7710_04780.grd
names : X1, X2, X3, X4, X5,
X6, X7
min values : 440.0467, 444.9182, 437.1589, 444.6946, 440.2028, 429.6900,
442.7436
max values : 563.8341, 561.7687, 560.4509, 565.8671, 560.1375, 561.7972,
556.2471
: 1, 2, 3, 4, 5, 6, 7
On 11/26/19 7:03 PM, Vijay Lulla wrote:
> If you read the code/help for `stackApply` and `zApply` you'll see
> that the results that you obtain make sense (at least they seem
> sensible/reasonable to me). IMO, if you want to control the ordering
> of your layers then just use sapply, like how you've used for
> ver_mean. IMO, this is the only reliable (safe?), and quite a
> readable, way to accomplish what you're trying to do.
> Just my 2 cents.
> -- Vijay.
>
> On Tue, Nov 26, 2019 at 11:19 AM Leonidas Liakos via R-sig-Geo
> <r-sig-geo using r-project.org <mailto:r-sig-geo using r-project.org>> wrote:
>
> I added raster::zApply in my tests to validate the results.
> However, the
> indices of the names of the results are different now. Recall that the
> goal is to calculate from a raster stack time series the mean per
> day of
> the week. And that problem I have is that stackApply, zApply and
> calc/sapply return different indices in the result names. New code is
> available here:
> https://gist.github.com/kokkytos/93f315a5ecf59c0b183f9788754bc170
> I'm really curious about missing something.
>
>
> On 11/20/19 3:30 AM, Frederico Faleiro wrote:
> > Hi Leonidas,
> >
> > both results are in the same order, but the name is different.
> > You can rename the first as in the second:
> > names(res) <- names(res2)
> >
> > I provided an example to help you understand the logic.
> >
> > library(raster)
> > beginCluster(2)
> > r <- raster()
> > values(r) <- 1
> > # simple sequential stack from 1 to 6 in all cells
> > s <- stack(r, r*2, r*3, r*4, r*5, r*6)
> > s
> > res <- clusterR(s, stackApply, args =
> list(indices=c(2,2,3,3,1,1), fun
> > = mean))
> > res
> > res2 <- stackApply(s, c(2,2,3,3,1,1), mean)
> > res2
> > dif <- res - res2
> > # exatly the same order because the difference is zero for all
> layers
> > dif
> > # rename
> > names(res) <- names(res2)
> >
> > Best regards,
> >
> > Frederico Faleiro
> >
> > On Tue, Nov 19, 2019 at 4:15 PM Leonidas Liakos via R-sig-Geo
> > <r-sig-geo using r-project.org <mailto:r-sig-geo using r-project.org>
> <mailto:r-sig-geo using r-project.org <mailto:r-sig-geo using r-project.org>>>
> wrote:
> >
> > I run the example with clusterR:
> >
> > no_cores <- parallel::detectCores() -1
> > raster::beginCluster(no_cores)
> > ?????? res <- raster::clusterR(inp, raster::stackApply, args =
> > list(indices=c(2,2,3,3,1,1),fun = mean))
> > raster::endCluster()
> >
> > And the result is:
> >
> > > res
> > class?????????? : RasterBrick
> > dimensions : 180, 360, 64800, 3?? (nrow, ncol, ncell, nlayers)
> > resolution : 1, 1?? (x, y)
> > extent???????? : -180, 180, -90, 90?? (xmin, xmax, ymin, ymax)
> > crs?????????????? : +proj=longlat +datum=WGS84 +ellps=WGS84
> > +towgs84=0,0,0
> > source???????? : memory
> > names?????????? : layer.1, layer.2, layer.3
> > min values :???????? 1.5,???????? 3.5,???????? 5.5
> > max values :???????? 1.5,???????? 3.5,???????? 5.5??
> >
> >
> > layer.1, layer.2, layer.3 (?)
> >
> > So what corrensponds to what?
> >
> >
> > If I run:
> >
> > res2 <- stackApply(inp,c(2,2,3,3,1,1),mean)
> >
> > The result is:
> >
> > > res2
> > class : RasterBrick
> > dimensions : 180, 360, 64800, 3 (nrow, ncol, ncell, nlayers)
> > resolution : 1, 1 (x, y)
> > extent : -180, 180, -90, 90 (xmin, xmax, ymin, ymax)
> > crs : +proj=longlat +datum=WGS84 +ellps=WGS84
> +towgs84=0,0,0
> > source : memory
> > names : index_2, index_3, index_1
> > min values : 1.5, 3.5, 5.5
> > max values : 1.5, 3.5, 5.5
> >
> > There is no consistency with the names of the output and obscure
> > correspondence with the indices in the case of clusterR
> >
> >
> > [[alternative HTML version deleted]]
> >
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