I am trying to export landscapemetrics output which is a sf dataframe as a raster, the first column of the df is the grid cell number, the second is the value and the third column has the polygon geometry as an sfc list. However when I write to raster I get the following error:

writeRaster(enn2mean,"enn2.tif") Error in (function (classes, fdef, mtable) : unable to find an inherited method for function ‘writeRaster’ for signature ‘"sf", "character"’

Here is my code:

# Code---------------------------------------------
my_raster = studyarea

# create new grid ---------------------------------------------------------
my_grid_geom = st_make_grid(st_as_sfc(st_bbox(my_raster)), cellsize = 2500) 

my_grid_template = st_sf(geom = my_grid_geom)

my_grid_template$plot_id = 1:nrow(my_grid_template)

# calculate patch metrics -------------------------------------------------
enn = sample_lsm(my_raster, my_grid_template,
                       level = "patch", metric = "enn", progress = TRUE)
# connect results to grid 
enn_grid = left_join(my_grid_template, enn, by = "plot_id")


#subset class 2

enn_grid2 <- subset(enn_grid, class==2)

enn2df = subset(enn_grid2, select = c(plot_id,value,geom) )

#calculate mean value of grid cell

enn2mean<-aggregate(enn2df[, 2:3], list(enn2df$plot_id), mean)

enn2plot<-plot(enn2mean["value"],main="Enn Class 2 Mean")

##I then want to export this as a tiff 
> class(enn2mean)

[1] "sf"         "data.frame"

> writeRaster(enn2mean,"enn2.tif")

Error in (function (classes, fdef, mtable) : unable to find an inherited method for function ‘writeRaster’ for signature ‘"sf", "character"’

  • As per the help center please don’t include chit chat like statements of appreciation within your posts here.
    – PolyGeo
    Commented Aug 11, 2021 at 7:27
  • I would recommend reading the help, vignettes, and primary literature carefully. I have no idea why you are creating a sample grid to create metrics but, you are introducing a notable aggregation (eg., MAUP) into your results. It is one thing to have plot data that you are using as a statistical sample but, something else entirely in creating a new grain to the data. Take a look at window_lsm. That said, your sf object is a vector and you cannot simply snap your fingers and have it be a raster, you need to rasterize it first. There are many posts regarding that on this forum. Commented Aug 11, 2021 at 12:59

1 Answer 1



[1] "sf" "data.frame"

Your file enn2mean is an sf, and writeRaster works with raster files only. You need to rasterize it, and then export it. This is one way to do it:

# open libraries

# rasterize based on geometry and a column named "value". Change the name of this column if necessary
r.enn2mean<-st_rasterize(enn2mean %>% dplyr::select(value, geometry))

# export as tiff
write_stars(r.enn2mean, "enn2mean.tif")

There are more option to customize your rasterization, check this out: https://r-spatial.github.io/stars/reference/st_rasterize.html

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.