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Compute Nearest Neighbour Distances

Source: R/spatial.R
nearest_neighbours.Rd

For each cell, computes the distance to the nearest neighbouring cell, optionally restricted to specific phenotypes.

Usage

nearest_neighbours(dt, target_phenotype = NULL, k = 1L)

Arguments

dt

A data.table with columns x and y.

target_phenotype

Character string or NULL. If provided, distances are computed only to cells of this phenotype. Requires a phenotype column.

k

Integer. Number of nearest neighbours to consider. Default 1.

Value

The input data.table with an added nn_distance column (mean distance to the k nearest neighbours).

Examples

dt <- data.table::data.table(
  sample_id = "s1", cell_id = 1:20,
  x = runif(20, 0, 100), y = runif(20, 0, 100)
)
result <- nearest_neighbours(dt, k = 3)
head(result[, .(cell_id, nn_distance)])
#>    cell_id nn_distance
#>      <int>       <num>
#> 1:       1   12.937976
#> 2:       2   11.203918
#> 3:       3   13.765183
#> 4:       4   20.192255
#> 5:       5   14.425834
#> 6:       6    7.784847