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Convert Irish grid references to Irish Grid coordinates

Source: R/igr_to_ig.R
igr_to_ig.Rd

igr_to_ig() converts Irish grid references into a list of Irish Grid (EPSG:29903) X and Y coordinates. By default the coordinates of the south west corners of each Irish grid reference are calculated. The precision of each Irish grid reference in metres can be returned.

Usage

igr_to_ig(
  x,
  coords = c("x", "y"),
  centroids = FALSE,
  precision = NULL,
  tetrad = TRUE
)

Arguments

x

A character vector of Irish grid references. See igr_is_valid() for a definition of valid Irish grid references.

coords

A character vector of the names of the columns to contain the Irish Grid X and Y coordinates respectively.

centroids

Should the coordinates of the centroids of the Irish grid references be returned (rather than the south west corners)?

precision

The name of the column to contain the precision of each Irish grid reference in metres, if required.

tetrad

Permit tetrad form of Irish grid reference?

Value

A list containing Irish Grid X and Y coordinates and, optionally, the precision in metres of each Irish grid reference. Invalid or missing Irish grid references return NA.

Examples

# A vector of Irish grid references of different precisions
v <- c("N8090", "D1234588800", "W34", "", "D12T")

# Convert south west corners of Irish grid references to Irish Grid coordinates
igr_to_ig(v)
#> Warning: Invalid Irish grid references detected: 
#> $x
#> [1] 280000 312345 130000     NA 316000
#> 
#> $y
#> [1] 290000 488800  40000     NA 426000
#> 

# Convert centroids of Irish grid references to Irish Grid coordinates
igr_to_ig(v, centroids = TRUE)
#> Warning: Invalid Irish grid references detected: 
#> $x
#> [1] 280500.0 312345.5 135000.0       NA 317000.0
#> 
#> $y
#> [1] 290500.0 488800.5  45000.0       NA 427000.0
#> 

# Specify column names
igr_to_ig(v, coords = c("e", "n"))
#> Warning: Invalid Irish grid references detected: 
#> $e
#> [1] 280000 312345 130000     NA 316000
#> 
#> $n
#> [1] 290000 488800  40000     NA 426000
#> 

# Also return the precision in metres of each Irish grid reference
igr_to_ig(v, precision = "prec")
#> Warning: Invalid Irish grid references detected: 
#> $x
#> [1] 280000 312345 130000     NA 316000
#> 
#> $y
#> [1] 290000 488800  40000     NA 426000
#> 
#> $prec
#> [1]  1000     1 10000    NA  2000
#>