I'm currently convert original matrix into a raster to use the focal function, then I would like to convert back the raster into matrix. But I have an error message when I try to use the raster function as.matrix(). Even with this very simple example:
r <- raster(ncol=3, nrow=3)
r[] <- 1:ncell(r)
as.matrix(r)
Here is what I got:
Error in array(x, c(length(x), 1L), if (!is.null(names(x))) list(names(x), :
length of 'dimnames' [1] not equal to array extent
I'm using RSTUDIO, R version 3.4.0 and ncdf4
, raster
and rgdal
librairies.
Thank you for your help.
Make sure that you're using the as.matrix
function from the raster
package, not the base version.
I assume you loaded the package with library
or require
:
library(raster)
r <- raster()
r[] <- 1:ncell(r)
When I use as.matrix
, it works:
> str(as.matrix(r))
int [1:180, 1:360] 1 361 721 1081 1441 1801 2161 2521 2881 3241 ...
When you use the base version of as.matrix
, you'll get exactly this error message:
> base::as.matrix(r)
Error in array(x, c(length(x), 1L), if (!is.null(names(x))) list(names(x), :
length of 'dimnames' [1] not equal to array extent
So if only loading the library doesn't work for you, try calling the function like this: raster::as.matrix(r)