RASTER TO VECTOR : WriteVector from terra package leads to fatal error

Question

I have this sampled code that I tried on RStudio these last days :

library ('terra')

binar <- rast("C:/Users/BIC_/Desktop/21_binarisation_SWIR.tif")
poly_rast <- as.polygons(binar , values = TRUE,extent=FALSE)

I want to convert my raster "binar" into a vector; I have tried with the function "rasterToPolygons" from the package "raster" but it was too long.

After 'vectorizing' my raster I wanted to export it as a shapefile, with this line :

writeVector(poly_rast, filename ="C:/Users/BIC_/Desktop/21_contour_im",filetype = "ESRI Shapefile")

But every time I am doing this it's leading me to a fatal error and R crashes. I do not know how to do and what I've done wrong.

Also I have notice that my poly_rast file has a 0x0 dimension, weird...

> binar
class       : SpatRaster 
dimensions  : 10980, 10980, 1  (nrow, ncol, nlyr)
resolution  : 10, 10  (x, y)
extent      : 3e+05, 409800, 7590220, 7700020  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=utm +zone=38 +south +datum=WGS84 +units=m +no_defs 
source      : 0121_binarisation_SWIR_MOROMBE_T38KLB.tif 
name        : 0121_binarisation_SWIR_MOROMBE_T38KLB 
min value   :                                     0 
max value   :                                     1

> poly_rast
 class       : SpatVector 
 geometry    : none 
 dimensions  : 0, 0  (geometries, attributes)
 extent      : -180, 180, -90, 90  (xmin, xmax, ymin, ymax)
 coord. ref. : +proj=utm +zone=38 +south +datum=WGS84 +units=m +no_defs

When plotting "poly_rast" to see what's returned this message appears and my plot window is blank :

Error in g[[i]] : subscript out of bounds

Thanks for your help !!

Can you please report the version of terra you are using? (is it the development version or at least the current version on CRAN)? — Robert Hijmans, Apr 21 '22 at 14:33

score 0 · Answer 1 · answered Apr 28 '22 at 05:46

This is probably a bug in a very old version of terra.

You are using 1.2-5 while the CRAN version is 1.5-21 --- so please update terra and report back. Using the current version is especially important if you report what appears to be a bug (bugs are best reported here).

You can also install the development version like this: install.packages('terra', repos='https://rspatial.r-universe.dev')

RASTER TO VECTOR : WriteVector from terra package leads to fatal error

1 Answers1