nominatim problem

nominatim_problem.R

<!-- language-all: lang-r -->


    library(nominatim)
    #> Data (c) OpenStreetMap contributors, ODbL 1.0. http://www.openstreetmap.org/copyright
    #> Nominatim Usage Policy: http://wiki.openstreetmap.org/wiki/Nominatim_usage_policy
    #> MapQuest Nominatim Terms of Use: http://info.mapquest.com/terms-of-use/
    library(sf)
    #> Linking to GEOS 3.6.1, GDAL 2.2.3, PROJ 4.9.3
    library(raster)
    #> Loading required package: sp
    library(tmap)

    # get OSM search results for Ashfield district (UK)
    ashfield <- nominatim::osm_search_spatial("Ashfield", limit = 1, key = "KtacQGOTApeFbfDhKaq5cGk8T16V4ioP")
    class(ashfield)
    #> [1] "list"

    # extract SPDF from list
    ashfield <- ashfield[[1]]
    class(ashfield)
    #> [1] "SpatialPolygonsDataFrame"
    #> attr(,"package")
    #> [1] "sp"
    raster::projection(ashfield)
    #> [1] NA
    # set projection
    tmap::qtm(ashfield, projection = "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs")
    #> Warning: The shape ashfield is invalid. See sf::st_is_valid
    #> Warning: Currect projection of shape ashfield unknown. Long-lat (WGS84) is
    #> assumed.

![](https://i.imgur.com/AjzVwrP.png)

    sf::st_is_valid(ashfield, reason = TRUE)
    #> Error in UseMethod("st_geometry"): no applicable method for 'st_geometry' applied to an object of class "c('SpatialPolygonsDataFrame', 'SpatialPolygons', 'Spatial', 'SpatialVector', 'SpatialPolygonsNULL')"
    raster::projection(ashfield) <- "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs"
    tmap::qtm(ashfield)
    #> Warning: The shape ashfield is invalid. See sf::st_is_valid

![](https://i.imgur.com/Rh0El4Q.png)


    # Convert to an SF object and try again
    ashfield_sf <- sf::st_as_sf(ashfield)
    class(ashfield_sf)
    #> [1] "sf"         "data.frame"
    tmap::qtm(ashfield_sf, projection = "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs")
    #> Warning: The shape ashfield_sf is invalid. See sf::st_is_valid

![](https://i.imgur.com/zzpeIbu.png)

    sf::st_is_valid(ashfield_sf, reason = TRUE)
    #> [1] "Self-intersection[53.0709899483331 53.0709561246412]"
    sf::st_transform(ashfield_sf, crs = 4326)
    #> Simple feature collection with 1 feature and 15 fields
    #> geometry type:  POLYGON
    #> dimension:      XY
    #> bbox:           xmin: -1.344593 ymin: -1.344593 xmax: 53.17143 ymax: 53.17142
    #> epsg (SRID):    4326
    #> proj4string:    +proj=longlat +datum=WGS84 +no_defs
    #>            place_id
    #> 186877616 186877616
    #>                                                                                        licence
    #> 186877616 Data © OpenStreetMap contributors, ODbL 1.0. https://www.openstreetmap.org/copyright
    #>           osm_type osm_id      lat       lon
    #> 186877616 relation 154043 53.08977 -1.251877
    #>                                                                display_name
    #> 186877616 Ashfield, Nottinghamshire, East Midlands, England, United Kingdom
    #>              class           type importance
    #> 186877616 boundary administrative  0.2116014
    #>                                                                                                                          icon
    #> 186877616 http://ip-10-98-162-13.mq-us-east-1.ec2.aolcloud.net/nominatim/images/mapicons/poi_boundary_administrative.p.20.png
    #>            bbox_left   bbox_top bbox_right bbox_bottom
    #> 186877616 53.0080617 53.1714343 -1.3445928  -1.1642542
    #>                                 geometry
    #> 186877616 POLYGON ((-1.344593 -1.3444...
    tmap::qtm(ashfield_sf)
    #> Warning: The shape ashfield_sf is invalid. See sf::st_is_valid

![](https://i.imgur.com/WtHEwYl.png)

<sup>Created on 2020-02-20 by the [reprex package](https://reprex.tidyverse.org) (v0.3.0)</sup>