GeoAI_2021_unit_03_EX_Spatial_prediction

[GeoKL]

Hello, whenever I try to run prediction <- raster::predict(rasterStack, ffsmodel, na.rm = TRUE) I get the Error message Warning in file(fn, "rb") : cannot open file 'C:\Users\Kathi\AppData\Local\Temp\RtmpyijrEy\raster\r_tmp_2021-12-01_121626_23620_45054.gri': No such file or directory Error in file(fn, "rb") : cannot open the connection

I tried reinstalling the raster package and running R as administrator.

The connection 'C:\Users\Kathi\AppData\Local\Temp\RtmpyijrEy\raster\r_tmp_2021-12-01_121626_23620_45054.gri' indeed does not exist (there is no RtmpyijrEy folder in Temp).

In the first code chunk of this EX I changed predictors = training[,3:9] to predictors = training[,2:9] to include the OBJ_ID column. Might that be the problem?

[GeoKL]

Hi, so I changed it back to predictors = training[,3:9] and ran the modell again and the chunk prediction <- raster::predict(rasterStack, ffsmodel, na.rm = TRUE) still does not run. Also it seems like other (or maybe all) raster functions do not work either. I always get this error message: Warning in file(fn, "rb") : cannot open file 'C:\Users\Kathi\AppData\Local\Temp\RtmpyijrEy\raster\r_tmp_2021-12-01_121626_23620_45054.gri': No such file or directory Error in file(fn, "rb") : cannot open the connection

I don't know what to do about this..

[gisma]

@GeoKL Actually the error message tells us that the predict function is not able to locate the raster stack file. You obvouisly did not run the setup function. At the end of the script a temporary folder is set which "stabilize" for raster operation . However in this case you are running the predict on a stack that one was in the temporary folder under your user account. You need to fix this to a non temporary folder.

[GeoKL]

Thanks, you're right, since there was already a setup included in the EX (which has now changed), I did not include my normal setup (next time I will). But I ran

set raster temp path

raster::rasterOptions(tmpdir = envrmt$path_tmp) before every try, which is what you mean by setting a temporary folder right?

Now I also included my normal setup skript and I still get the Error message. For example, when I try to run

raster::plotRGB(rasterStack) Warning in file(fn, "rb") : cannot open file 'C:\Users\Kathi\AppData\Local\Temp\RtmpyijrEy\raster\r_tmp_2021-12-01_121626_23620_45054.gri': No such file or directory Error in file(fn, "rb") : cannot open the connection

So you said, I have to fix my folder to a non temporary folder. How do I do that?

[gisma]

• the option

  ##set temp path to speed up raster package operations
  raster::rasterOptions(tmpdir = envrmt$path_tmp)

  is helpful to control the temporary folder of raster package operations.

• the problem is that raster is writing a temporary file of your prediction stack. This is helpful if you run on a poor working memory. However it is often a problem because the temporary folders are often "unlinked" or "lost" - especially if you restart resessions etc.

[Muenchj4]

@gisma I tried to run the forward feature selection model based on leave location out cross validation with my extracted data consisting of 20 polygons (10 of class "building" and 10 of class "other"). But it was not able to finish and told me: "Something is wrong; all the Accuracy metric values are missing: Accuracy Kappa
Min. : NA Min. : NA
1st Qu.: NA 1st Qu.: NA
Median : NA Median : NA
Mean :NaN Mean :NaN
3rd Qu.: NA 3rd Qu.: NA
Max. : NA Max. : NA
NA's :1 NA's :1
Error: Stopping In addition: There were 11 warnings (use warnings() to see them)" How can I tackle this problem and how can I put the accuracy metric values into the model to calculate on their base?

[Muenchj4]

@gisma I now tried to run the ramdomly_goog_model script bevor and hoped the accuracy value would be used in the ffsmodel, but this time I got the message: Error in summary.connection(connection) : invalid connection What could be the reason? And how can I transfer this obvious invalid connection into a valid connection?