This helper patches a bug/feature in ODK Central (versions 0.7-0.9), where geotrace / geoshape GeoJSON contains a last coordinate pair with NULL lat/lon (no alt/acc), and WKT ends in , undefined NaN.

drop_null_coords(x)

Arguments

x

A GeoJSON geometry parsed as nested list. E.g. geo_gj$path_location_path_gps.

Value

The nested list minus the last element (if NULL).

Details

While split_geotrace and split_geoshape modify the WKT inline, it is more maintainable to separate the GeoJSON cleaner into this function.

This helper drops the last element of a GeoJSON coordinate list if it is list(NULL, NULL).

See also

Examples

# A snapshot of geo data with trailing empty coordinates. data("geo_gj88") len_coords <- length(geo_gj88$path_location_path_gps[[1]]$coordinates) length(geo_gj88$path_location_path_gps[[1]]$coordinates[[len_coords]]) %>% testthat::expect_equal(2) geo_gj88$path_location_path_gps[[1]]$coordinates[[len_coords]][[1]] %>% testthat::expect_null() geo_gj88$path_location_path_gps[[1]]$coordinates[[len_coords]][[2]] %>% testthat::expect_null() # The last coordinate pair is a list(NULL, NULL). # Invalid coordinates like these are a choking hazard for geospatial # packages. We should remove them before we can convert ODK data into native # spatial formats, such as sf. str(geo_gj88$path_location_path_gps[[1]]$coordinates[[len_coords]])
#> List of 2 #> $ : NULL #> $ : NULL
geo_gj_repaired <- geo_gj88 %>% dplyr::mutate( path_location_path_gps = path_location_path_gps %>% purrr::map(drop_null_coords) ) len_coords_repaired <- length( geo_gj_repaired$path_location_path_gps[[1]]$coordinates ) testthat::expect_equal(len_coords_repaired + 1, len_coords)