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mapirosa

Access OS OpenData APIs From R

A package to enable accessing basemap tiles from the OS Maps API, initially. Access to other OS (Ordnance Survey) Data Hub APIs may follow. The primary motivation for this project was to find a map tile service that supplies tiles in the British National Grid (27700) CRS, unlike the usual web mapping standard CRS of 3857. The name of the package is an intentional corruption of the Spanish word mariposa 🦋.

two butterfly shapes cut out from paper maps

Installation

remotes::install_github("francisbarton/mapirosa")

To use the package you will need to have an API key from the Ordnance Survey website. Save this as an environment variable called OS_DATA_KEY

The easiest way to do this is to add a line to your .Renviron file like:

OS_DATA_KEY = abcd1234

Create basemaps using raster data (PNGs)

Examples:

library(mapirosa)

if (requireNamespace("osmdata")) {
  oxford1 <- create_bbox("Oxford", 27700)
} else {
  oxford1 <- c(
    xmin = 448100.3,
    ymin = 201646.6,
    xmax = 457014.2,
    ymax = 211088.8
  )
}
#> Loading required namespace: osmdata

oxford_basemap1 <- build_basemap(
  bbox = oxford1,
  zoom = 5,
  style = "road",
  squarify = FALSE,
  crs = 27700
)
oxford_basemap1
#> class       : SpatRaster 
#> dimensions  : 512, 768, 3  (nrow, ncol, nlyr)
#> resolution  : 28, 28  (x, y)
#> extent      : 442585, 464089, 200704, 215040  (xmin, xmax, ymin, ymax)
#> coord. ref. : OSGB36 / British National Grid (EPSG:27700) 
#> source(s)   : memory
#> names       : lyr.1, lyr.2, lyr.3 
#> min values  :     0,     0,     0 
#> max values  :     1,     1,     1
if (requireNamespace("tmap")) {
  suppressMessages(tmap::tmap_mode("plot"))
  tmap::tm_shape(oxford_basemap1, raster.downsample = FALSE) +
    tmap::tm_rgb(max.value = 1)
}
#> Loading required namespace: tmap

if (requireNamespace("osmdata", quietly = TRUE)) {
  oxford2 <- create_bbox("Oxford", 3857)
} else {
  oxford2 <- c(
    xmin = -145188.1,
    ymin = 6748034.5,
    xmax = -130890.9,
    ymax = 6763371.2)
}

oxford_basemap2 <- build_basemap(
  bbox = oxford2,
  zoom = 12,
  style = "outdoor",
  squarify = TRUE,
  crs = 3857
)
oxford_basemap2
#> class       : SpatRaster 
#> dimensions  : 768, 768, 3  (nrow, ncol, nlyr)
#> resolution  : 38.21882, 38.21882  (x, y)
#> extent      : -146760.3, -117408.2, 6741189, 6770541  (xmin, xmax, ymin, ymax)
#> coord. ref. : WGS 84 / Pseudo-Mercator (EPSG:3857) 
#> source(s)   : memory
#> names       :      lyr.1,     lyr.2,      lyr.3 
#> min values  : 0.03137255, 0.1411765, 0.02745098 
#> max values  : 1.00000000, 1.0000000, 1.00000000
# tidyterra: https://dieghernan.github.io/tidyterra/reference/geom_spatraster_rgb.html)

if (requireNamespace("ggplot2") & requireNamespace("tidyterra")) {
  ggplot2::ggplot() +
    tidyterra::geom_spatraster_rgb(
      data = oxford_basemap2,
      maxcell = 1e7,
      max_col_value = 1) +
    ggplot2::coord_sf() +
    ggplot2::theme_void()
}
#> Loading required namespace: ggplot2
#> Loading required namespace: tidyterra

Names API

The spec for the Names API can be found on the OS website here.

Currently we just use the find endpoint. The nearest endpoint may be added later.

Without a bounds argument, the function will search nationally. You can specify how many results you want to receive (up to a maximum of 100).

query_names_api("Summertown", local_types = "Suburban Area", max_results = 2) |>
  tibble::glimpse()
#> Rows: 2
#> Columns: 28
#> $ id                    <chr> "osgb4000000074309758", "osgb4000000074546671"
#> $ names_uri             <chr> "http://data.ordnancesurvey.co.uk/id/40000000743…
#> $ name1                 <chr> "Summertown", "Summertown"
#> $ type                  <chr> "populatedPlace", "populatedPlace"
#> $ local_type            <chr> "Suburban Area", "Suburban Area"
#> $ geometry_x            <dbl> 255845, 451045
#> $ geometry_y            <dbl> 665095, 208698
#> $ most_detail_view_res  <int> 6000, 10000
#> $ least_detail_view_res <int> 25000, 25000
#> $ mbr_xmin              <dbl> 255457, 450317
#> $ mbr_ymin              <dbl> 664710, 207986
#> $ mbr_xmax              <dbl> 256214, 451644
#> $ mbr_ymax              <dbl> 665574, 209560
#> $ postcode_district     <chr> "G51", "OX2"
#> $ postcode_district_uri <chr> "http://data.ordnancesurvey.co.uk/id/postcodedis…
#> $ county_unitary        <chr> "Glasgow City", "Oxfordshire"
#> $ county_unitary_uri    <chr> "http://data.ordnancesurvey.co.uk/id/70000000000…
#> $ county_unitary_type   <chr> "http://data.ordnancesurvey.co.uk/ontology/admin…
#> $ region                <chr> "Scotland", "South East"
#> $ region_uri            <chr> "http://data.ordnancesurvey.co.uk/id/70000000000…
#> $ country               <chr> "Scotland", "England"
#> $ country_uri           <chr> "http://data.ordnancesurvey.co.uk/id/country/sco…
#> $ district_borough      <chr> NA, "Oxford"
#> $ district_borough_uri  <chr> NA, "http://data.ordnancesurvey.co.uk/id/7000000…
#> $ district_borough_type <chr> NA, "http://data.ordnancesurvey.co.uk/ontology/a…
#> $ same_as_geonames      <chr> NA, "http://sws.geonames.org/2636537"
#> $ same_as_dbpedia       <chr> NA, "http://dbpedia.org/resource/Summertown,_Oxf…
#> $ geometry              <POINT [m]> POINT (255845 665095), POINT (451045 208698)…

To restrict results to a certain area, use the bounds argument with a “bbox” (the create_bbox() function can help you).

Use OS National Grid (CRS 27700) numbers for your bbox.

query_names_api("Summertown", "Suburban Area", bounds = oxford1) |>
  tibble::glimpse()
#> Rows: 1
#> Columns: 28
#> $ id                    <chr> "osgb4000000074546671"
#> $ names_uri             <chr> "http://data.ordnancesurvey.co.uk/id/40000000745…
#> $ name1                 <chr> "Summertown"
#> $ type                  <chr> "populatedPlace"
#> $ local_type            <chr> "Suburban Area"
#> $ geometry_x            <dbl> 451045
#> $ geometry_y            <dbl> 208698
#> $ most_detail_view_res  <int> 10000
#> $ least_detail_view_res <int> 25000
#> $ mbr_xmin              <dbl> 450317
#> $ mbr_ymin              <dbl> 207986
#> $ mbr_xmax              <dbl> 451644
#> $ mbr_ymax              <dbl> 209560
#> $ postcode_district     <chr> "OX2"
#> $ postcode_district_uri <chr> "http://data.ordnancesurvey.co.uk/id/postcodedis…
#> $ district_borough      <chr> "Oxford"
#> $ district_borough_uri  <chr> "http://data.ordnancesurvey.co.uk/id/70000000000…
#> $ district_borough_type <chr> "http://data.ordnancesurvey.co.uk/ontology/admin…
#> $ county_unitary        <chr> "Oxfordshire"
#> $ county_unitary_uri    <chr> "http://data.ordnancesurvey.co.uk/id/70000000000…
#> $ county_unitary_type   <chr> "http://data.ordnancesurvey.co.uk/ontology/admin…
#> $ region                <chr> "South East"
#> $ region_uri            <chr> "http://data.ordnancesurvey.co.uk/id/70000000000…
#> $ country               <chr> "England"
#> $ country_uri           <chr> "http://data.ordnancesurvey.co.uk/id/country/eng…
#> $ same_as_geonames      <chr> "http://sws.geonames.org/2636537"
#> $ same_as_dbpedia       <chr> "http://dbpedia.org/resource/Summertown,_Oxford"
#> $ geometry              <POINT [m]> POINT (451045 208698)

Features API

The spec for the Features API can be found on the OS website here.

query_features_api() is designed to work with this API. Unfortunately it is not yet functional.

Documentation to follow.