I'm using R to run a random forest to predict the distribution of sediment classes in a study area. I have a .csv of the locations where sediment has been sampled, and rasters of all my predictor variables.

bbpi <- raster("broadbpi_st.tif")
east <- raster("eastness.tif")
fbpi <- raster("finebpi_st.tif")
bath <- raster("gebco_bathymetry.tif")
north <- raster("northness.tif")
curd <- extractByMask(raster("current_direction.tif"), msk= bath, spatial = TRUE)
curm <- extractByMask(raster("current_magnitude.tif"), msk=bath, spatial=TRUE)
#rug <- raster("rugosity.tif")
slope <- extractByMask(raster("slope_final.tif"), msk=bath, spatial=TRUE)
area <- extractByMask(raster("surface_planar_arearatio.tif"), msk=bath, spatial=TRUE)
umean <- extractByMask(raster("ustar_mean.tif"),msk=bath, spatial=TRUE)
umax <- extractByMask(raster("ustarmax_IDW.tif"),msk=bath, spatial=TRUE)
wmax <- extractByMask(raster("wavepower_max_IDW.tif"),msk=bath, spatial=TRUE)
wmean <- extractByMask(raster("wavepower_mean.tif"),msk=bath, spatial=TRUE)
rfstack <- stack(bbpi,fbpi,bath,east,north,curd,curm,slope,area,umean,umax,wmax,wmean)
names(rfstack) <- c("bbpi","fbpi","bath","east","north","curd","curm","slope","area","umean","umax","wmax","wmean")

points <- read.csv("bottomgrabs.csv")
rf1 <- randomForest(factor(DEPOT_GRO) ~ ., data=points, ntree=500, mtry=10, na.action=na.omit)

test1 <- raster::predict(rf1,newdata=rfstack,type="prob")

I get the following error:

Error in as.data.frame.default(newdata) : cannot coerce class ‘structure("RasterStack", package = "raster")’ to a data.frame

How do I fix this and make my random forest run?

1 Answer 1


You should be able to get this to run by converting the raster stack yourself. For example, I've replicated your error with a trivial test data set:

> raster::predict(rf1, newdata=rstack)
Error in as.data.frame.default(newdata) : 
  cannot coerce class ‘structure("RasterStack", package = "raster")’ to a data.frame

and this runs:

> raster::predict(rf1, newdata=as.data.frame(rstack))
 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 
 B  C  C  C  A  A  A  A  C  A  A  A  C  B  A  A 
Levels: A B C
  • The solution you gave returns a different error: Error in eval(predvars, data, env) : object 'ï..OID_' not found
    – Emily
    Commented Jan 20, 2022 at 17:28
  • That's probably a column in your fitted data (the CSV) that you don't have new data for (in the form of the name of a layer in your raster stack). Can't really debug that without all of your data sets, or more info about what you do have. I think my answer fixes the the initial problem so you should mark this as correct, then see if you can fix the subsequent error, and if not then post a new question.
    – Spacedman
    Commented Jan 20, 2022 at 17:35
  • 1
    yes, I fixed the follow up error. Thank you for your help!
    – Emily
    Commented Jan 20, 2022 at 17:57

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