terra | R package for spatial data handling https | Data Visualization library

I am using the focal function in the terra package to fill holes in a DEM raster. However, after running focal(m, w=19, fun=mean, na.policy="only", na.rm=TRUE) my DEM is moved ~11cm relative to it's original position (see images below). This problem does not occur when I simply read in the raster using rast() and then write it using writeRaster(), but it happens when I use focal() regardless of whether I save the output using writeRaster() or using the filename = argument within focal().

I have also noticed that the larger the window size used, the greater the movement of the output raster. A window size of 9 produced ~5cm error. Raster pixels are ~1.2cm in size so focal() appears to be causing a movement of ~1/2 the width of the window used. As far as I can tell the movement is straight up/north.

Any idea why this might be occuring and how it could be avoided?

This the correctly aligned raster:

And this is after running focal (w = 19):

I am trying to count the non-NA values in a spatRaster using the global() function from the terra package. All the functions (mean, max, sd, etc.) seem to work except for "isNA" and "notNA". For these two functions it returns this error: Error in fun(values(x[[i]]), ...) : could not find function "fun", which is the same error it returns for a misspelled/non-existent function.

Is there a way to have the plot legend categories in a specific order with a SpatVector map of package terra? Example:

I want to crop a raster using a bbox or a known extent, i.e., 10 pixels in row and col.

Below you can see a reproducible example:

I want to select a group of pixels from a raster.

• The user should enter an n value for selecting the number of columns and rows (or window size).

• A window would fetch the number of pixels defined.

• Would return a raster with the values.

Below is a piece of reproducible example:

I want to perform a neighborhood analysis in R to smooth the layer I have but keeping all the NAs of the input raster intact.

However, when I do, for instance, the following, the calculation "propagates" over the NA values - what it is an undesiderable behavior, in my case.

With terra I would like to place the legend horizontally below the map. From help it seems that this can be done by either passing a character to legend (e.g. legend = "bottomleft") or by passing a list to plg with arguments from the base-R legend function. However, for me none of these work. Please, see code sample below.

Thanks!

I have the following problem. I want to build a model for landcover classification. My data are multitemporal Remote Sensing data with several bands. For training I created stratified randomly distributed points to extract spectral data at their positions. With these data a Random Forrest (Rpart) was trained using mlr3 package. For accuracy measurement a repeated spatial cross validation using mlr3spatiotempcv was performed. The resulting model of the training step is, after extraction, stored in an R Object of type rpart. In the terms field of this object are the variable names stored. These are all my used bands but also the spatial x and y coordinates. This brings problems when predicting new data. I used terra package and got an error the x and y layer are missing in my input data. Which kind of makes sense because they are stored in the terms field of the model. But from my understanding, the coordinates should not be a variable of the model. The coordinates are just used for spatial resampling and not for predicting. I "solved" this problem by removing x and y coordinates during the training process and perform just an ordinary non-spatial cross validation. After that I performed the prediction and it works perfectly.

So, my Question is, how can I train a model, using mlr3 package, with data containing coordinates, to perform spatial cross validation?, and then use this model to predict a new Raster.

I am trying to select several rasters from a SpatRasterDataset using the terra package in R. However when I try to select x rasters at once, the names show only the first x raster names, regardless of which rasters I try to select. Selecting a single raster seems to work fine, although the name given to it is not present.

So how do I properly subset a SpatRasterDataset keeping the correct names associated with rasters?

Reproducible example: