weird changes to coordinates from topo2geo(geo2topo(x))

[osserman]

Session Info

R version 3.5.1 (2018-07-02) Platform: x86_64-apple-darwin15.6.0 (64-bit) Running under: macOS 10.15.2 Matrix products: default BLAS: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib LAPACK: /Library/Frameworks/R.framework/Versions/3.5/Resources/lib/libRlapack.dylib locale: [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] geojsonio_0.8.0 sp_1.3-1 RPostgreSQL_0.6-2 DBI_1.0.0.9001 loaded via a namespace (and not attached): [1] remotes_2.0.0 sf_0.6-3 lattice_0.20-35 [4] testthat_2.0.0 V8_2.0 usethis_1.4.0 [7] yaml_2.2.0 base64enc_0.1-3 rlang_0.4.0 [10] pkgbuild_1.0.2 geojsonlint_0.3.0 e1071_1.7-0 [13] pillar_1.4.2 glue_1.3.1 foreign_0.8-70 [16] httpcode_0.2.0 withr_2.1.2 sessioninfo_1.1.0 [19] rgeos_0.5-2 devtools_2.0.0 memoise_1.1.0 [22] callr_3.0.0 maptools_0.9-8 ps_1.1.0 [25] curl_4.0 class_7.3-14 Rcpp_1.0.2 [28] readr_1.1.1 backports_1.1.4 classInt_0.2-3 [31] jsonvalidate_1.0.0 desc_1.2.0 pkgload_1.0.1 [34] jsonlite_1.6 fs_1.2.6 hms_0.4.2 [37] digest_0.6.20 stringi_1.4.3 processx_3.2.0 [40] grid_3.5.1 rprojroot_1.3-2 jqr_1.1.0 [43] rgdal_1.4-3 cli_1.1.0 tools_3.5.1 [46] magrittr_1.5 lazyeval_0.2.1 geojson_0.3.2 [49] tibble_2.1.3 crul_0.7.0 crayon_1.3.4 [52] pkgconfig_2.0.2 prettyunits_1.0.2 spData_0.2.9.4 [55] getcartr_1.01 assertthat_0.2.1 httr_1.4.0 [58] rstudioapi_0.7 R6_2.4.0 units_0.6-0 [61] compiler_3.5.1

I was seeing some really weird behavior where coordinates were totally mangled when I converted topojson back to geojson. I tried to do a bit of debugging to see what cases it was happening in or figure out more and seems to be happening even in the simplest of cases:

x <- '{"type": "LineString", "coordinates": [ [100.0, 0.0], [101.0, 1.0], [102.0, 1.0] ]}'
x2 <- topo2geo(geo2topo(x))
summary(x2)

produces: {"type":"FeatureCollection","features":[{"type":"Feature","properties":{"id":"foo"},"geometry":{"type":"LineString","coordinates":[[100,0],[201,1],[303,2]]}}]}

Going through another loop:

x3 <- topo2geo(geo2topo(2))
summary(x3)

produces: {"type":"FeatureCollection","features":[{"type":"Feature","properties":{"id":"foo"},"geometry":{"type":"LineString","coordinates":[[100,0],[301,1],[604,3]]}}]}

Thanks in advance!

[sckott]

thanks for this @osserman !

however, I can't replicate the problem, either with the current version of geojsonio on cran or the development version. I haven't tried it with your version of R, but I don't think that would cause any issues.

geojsonio doesn't define a summary method - what summary method is being called? there's a lot of pkgs loaded, so hard to know what s3 method is being used

[osserman]

Thanks @sckott for the quick reply.

Interesting that not reproducible.

Summary was just the first method I tried that actually output the json string. Looks like it's base or sp summary method that is being called (I get the same output from base::summary(x3) and sp::summary(x3)). But I don't think it's about the summary, since I also get the same output with cat(x3) and same changed coordinates when I convert it from geojson to sp.

Let me know if anything else would be useful for me to look into on my end.

Thanks again! Stephen

[sckott]

So it is indeed the R version you're running. I tested on R 3.5 and I now get your result. It must be something about that R version that is causing the issue. Can you upgrade to the latest R version?

the topo2geo uses internally sf::st_read - i see you're using an older version of sf from 2018. its possible sf then didn't have topojson support, not sure.

anyway, upgrading to the most recent R and sf would be a good idea

[osserman]

Sure enough -- that did it. Sorry I hadn't tried that for and thanks for tracking it down!

[github-actions[bot]]

This issue has been automatically locked. If you believe you have found a related problem, please file a new issue (with a reprex: https://reprex.tidyverse.org) and link to this issue.