rgisspatialterra

How to assign geometry type "polygons" to SpatVector with "null" geometry type using the terra package in R?

I have a series with shapefiles (not created by me) that I want to merge together. I am opening them with the terra package in R as a list of SpatVectors. However, when I try to merge them, I get the following error message:

Error: [vect] all SpatVectors must have the same geometry type

I found out (by running geomtype()) that one of my SpatVectors has geometry type "null", while the other ones are "polygons". How can I assign the same geometry type ("polygons") to the SpatVector without one?

I have tried the below, but none of them worked:

null_geometry_type_SpatVector <- 
    vect("null_geometry_type_SpatVector.shp", type="polygons")

geomtype(null_geometry_type_SpatVector) <- 
   geomtype(polygons_geometry_type_SpatVector)

Where polygons_geometry_type_SpatVector refers to a SpatVector I have with the correct geometry type.

geomtype(null_geometry_type_SpatVector) <- "polygons"

UPDATE:

Following an answer below, I have tried:

i <- emptyGeoms(null_geometry_type_SpatVector)
null_geometry_type_SpatVector_cleaned <- null_geometry_type_SpatVector[!i]

The commands run, but I am not sure what to do next. My goal is to be able to merge null_geometry_type_SpatVector with the other SpatVectors I have in my list (each SpatVector is a county in the US and merged together they form a state). So I believe I have to assign geometry type "polygons" to null_geometry_type_SpatVector_cleaned so I am able to merge it with the other SpatVectors and plot the merged SpatVector, but I still don't know how to do it. Any suggestions?

UPDATE 2:

The file that I am using that had NULL geometry is this one.

Solution

  • Thank you for providing an example file. With that file, I get

    x <- vect("clu_public_a_ne165.shp")
geomtype(x)
#[1] "null"

    You can fix that with

    x <- na.omit(x, geom=TRUE)

geomtype(x)
#[1] "polygons"

    Or with

    x <- vect("clu_public_a_ne165.shp")
i <- emptyGeoms(x)
x <- x[-i]

geomtype(x)
#[1] "polygons"

    And then proceed with x.

    This does mean that you lose the records that do not have an associated geometry.

    If you do not want that to happen, you can use the terra 1.7-32. This is currently the development version that you can install with

    install.packages('terra', repos='https://rspatial.r-universe.dev')

    With that version you should not get an error message at all when you use rbind (that is what I assume you are using).