ms_simplify() not preserving data: converting logical to NA

[jkennedyie]

Hi. The data in an sf object that I loaded with sf::st_readf() is not being preserved by ms_simplify() with defaults on rmapshaper 0.5.0.

Seem to have isolated the problem to feature 4 or 5 in attached geojson file...couldn't upload geojson so here it is with .txt extension:

rm_sharper_test.geojson.txt

Just looking at first 4 features, Current is False as expected

st_read("rm_sharper_test.geojson") |>
	slice_head(n = 4) |>
	ms_simplify() |>
	select(Current)

  Current                       geometry
1   FALSE POLYGON ((606251.1 917987.8...
2   FALSE POLYGON ((607071.2 919101.6...
3   FALSE POLYGON ((595753.3 902791.1...
4   FALSE POLYGON ((638244.3 939982.9...

But looking at 5 features, Current is NA for everything:

st_read("rm_sharper_test.geojson") |>
	slice_head(n = 5) |>
	ms_simplify() |>
	select(Current)

  Current                       geometry
1      NA POLYGON ((606251.1 917987.8...
2      NA POLYGON ((607071.2 919101.6...
3      NA POLYGON ((595753.3 902791.1...
4      NA POLYGON ((638244.3 939982.9...
5      NA POLYGON ((572453.1 909521.4...

Features seem valid. I wonder if related to #102.

Thanks

[ateucher]

Hi @jkennedyie thanks for reporting this. It looks like it is an issue in geojsonsf where logicals are being converted to character as "0"/"1", which are subsequently converted to NA when rmapshaper tries to restore the classes.

I'll open an issue in geojsonsf. Here's the crux of the problem:

gj <- '{"type":"FeatureCollection","features":[
  {"type":"Feature","properties":{"a":true},"geometry":{"type":"Point","coordinates":[0.0,0.0]}},
  {"type":"Feature","properties":{"a":false},"geometry":{"type":"Point","coordinates":[1.0,1.0]}}
]}'

sf <- geojsonsf::geojson_sf(gj)
sf
#>   a geometry
#> 1 1     0, 0
#> 2 0     1, 1
class(sf$a)
#> [1] "character"

as.logical(sf$a)
#> [1] NA NA

^{Created on 2025-11-07 with reprex v2.1.1}

[ateucher]

Reported here: SymbolixAU/geojsonsf#103

[ateucher]

We have a fix in SymbolixAU/geojsonsf#104

[ateucher]

@jkennedyie can you test this out with the new development version? Install with:

remotes::install_github("ateucher/rmapshaper")

It is working for me now

[ateucher]

Closing with #180

[jkennedyie]

Many thanks for hunting this down. Your latest versions github and cran both working for me now.

[ateucher]

Excellent, thanks for verifying. I've released the new version to CRAN now so you should be able to get it via the normal means.