Get the easting of a grid reference

This function returns the grid reference's easting in metres.

easting(x, ...)

# S3 method for gridref
easting(grid_reference, centre = FALSE)

Arguments

grid_reference	A Great British or Irish grid reference character string with class gridref.
centre	Should the easting be for the lower left hand corner (default FALSE) or the centre point (TRUE).

Value

The easting of grid reference in metres.

Details

It can check either British or Irish grid references up to 10 figure (1m precision), including tetrads (2000m precision).

REST API

A REST API endpoint is available once a Plumber router has been created and can be requested by adding _api to the end of the function.

The API returns "" instead of NULL so that it may be used with the dplyr::mutate function. Wrap the API call with dplyr::na_if to convert "" to NA.

suppressPackageStartupMessages({
  library(store)
  suppressWarnings({
    library(plumber)
  })
})
pr("../R/gridref_api.R") %>%
  pr_run(port = 8000)

See also

Other grid reference functions: gridsquare_geometry(), hectad(), hectare(), monad(), northing(), pentad(), precision(), projection(), tetrad()

Examples

 suppressPackageStartupMessages({
   library(store)
   suppressWarnings({
     library(dplyr)
     library(janitor)
   })
 })

 grid_references <- nbn_demonstration_dataset %>%
   clean_names() %>%
   slice_tail(n = 15) %>%
   select(grid_reference) %>%
   mutate(grid_reference = as_gridref(grid_reference))


# add easting column for the centre point
suppressPackageStartupMessages({
  suppressWarnings({
    library(dplyr)
  })
})

grid_references %>%
  rowwise() %>%
  mutate(easting_corner = easting(grid_reference),
         easting_centre = easting(grid_reference, centre = TRUE))
#> # A tibble: 15 x 3
#> # Rowwise: 
#>    grid_reference easting_corner easting_centre
#>    <gridref>               <dbl>          <dbl>
#>  1 TL2384                 523000         523500
#>  2 TL232839               523200         523250
#>  3 TL2385                 523000         523500
#>  4 TL231840               523100         523150
#>  5 TL232839               523200         523250
#>  6 TL23248346             523240         523245
#>  7 TL23568493             523560         523565
#>  8 TL23448505             523440         523445
#>  9 TL23128324             523120         523125
#> 10 TL234850               523400         523450
#> 11 TL234846               523400         523450
#> 12 TL232839               523200         523250
#> 13 TL231841               523100         523150
#> 14 TL226846               522600         522650
#> 15 TL2384                 523000         523500