Creating an sf spatial data frame from a data table, and then running split on it using a column for the split results in either an error or the object being split by columns instead of rows.
Example
library(data.table)
library(sf)
d = data.table(x=1:10, y=1:10, s=sample(1:2, 10, TRUE))
dsf = st_as_sf(d, coords=1:2)
split(d, d$s)
$`1`
x y s
1: 5 5 1
2: 8 8 1
3: 9 9 1
$`2`
x y s
1: 1 1 2
2: 2 2 2
3: 3 3 2
4: 4 4 2
5: 6 6 2
6: 7 7 2
7: 10 10 2
split(dsf, dsf$s)
# Error in `[.data.frame`(x, i) : undefined columns selected
Works fine if d is a data.frame:
d = data.frame(x=1:10, y=1:10, s=sample(1:2, 10, TRUE))
dsf = st_as_sf(d, coords=1:2)
split(dsf, dsf$s)
$`1`
Simple feature collection with 2 features and 1 field
Geometry type: POINT
[etc]
Related twitter thread here: https://twitter.com/michael_chirico/status/1512116488492048393?s=20&t=WSUB5c9_zI7suQNPjIFS6Q
# Output of sessionInfo()
> sessionInfo()
R version 4.1.1 (2021-08-10)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 20.04.3 LTS
Matrix products: default
BLAS: /opt/R-4.1.1/lib/R/lib/libRblas.so
LAPACK: /opt/R-4.1.1/lib/R/lib/libRlapack.so
locale:
[1] LC_CTYPE=en_GB.UTF-8 LC_NUMERIC=C
[3] LC_TIME=en_GB.UTF-8 LC_COLLATE=en_GB.UTF-8
[5] LC_MONETARY=en_GB.UTF-8 LC_MESSAGES=en_GB.UTF-8
[7] LC_PAPER=en_GB.UTF-8 LC_NAME=C
[9] LC_ADDRESS=C LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_GB.UTF-8 LC_IDENTIFICATION=C
attached base packages:
[1] stats graphics grDevices utils datasets methods base
other attached packages:
[1] sf_1.0-5 data.table_1.14.2
loaded via a namespace (and not attached):
[1] Rcpp_1.0.7 magrittr_2.0.1 units_0.7-2 tidyselect_1.1.1
[5] R6_2.5.1 rlang_0.4.12 fansi_0.5.0 dplyr_1.0.7
[9] tools_4.1.1 grid_4.1.1 KernSmooth_2.23-20 utf8_1.2.2
[13] e1071_1.7-9 DBI_1.1.1 ellipsis_0.3.2 class_7.3-19
[17] assertthat_0.2.1 tibble_3.1.4 lifecycle_1.0.1 crayon_1.4.2
[21] purrr_0.3.4 vctrs_0.3.8 glue_1.5.0 proxy_0.4-26
[25] compiler_4.1.1 pillar_1.6.3 generics_0.1.0 classInt_0.4-3
[29] pkgconfig_2.0.3
>
Creating an sf spatial data frame from a data table, and then running
spliton it using a column for the split results in either an error or the object being split by columns instead of rows.Example
Works fine if
dis a data.frame:Related twitter thread here: https://twitter.com/michael_chirico/status/1512116488492048393?s=20&t=WSUB5c9_zI7suQNPjIFS6Q
#Output of sessionInfo()