# dist2point: Calculate distance to points surfaces In rsh249/rasterExtras: Parallel computing with rasters

## Description

This function calculates the minimum distance to points raster.

## Usage

 ```1 2``` ```dist2point(grid, points, parallel = TRUE, nclus = 4, dist.method = "Haversine", maxram = 4) ```

## Arguments

 `grid` A raster object to match. `points` A two column data frame in the form (lon,lat) or (x,y) `parallel` TRUE or FALSE, should this code be executed in parallel. `nclus` IF parallel==TRUE then how many cores in the cluster. `dist.method` Which distance should we use? Haversine for lat/long projections,or Pythagorean for flat images and/or small areas. `maxram` Maximum theoretical RAM usage. Will be divided by nclus for parallel jobs.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13``` ```require(raster) grid = raster::raster(nrows=81, ncols=162, xmn=-180, xmx=180, ymn=-90, ymx=90, vals=NULL) grid = raster::setValues(grid,values=(as.vector(seq(1:raster::ncell(grid))))) points = cbind( c(seq(xmin(grid), xmax(grid), length.out=1000), seq(xmax(grid), xmin(grid), length.out=1000)), c(seq(ymin(grid), ymax(grid), length.out=100), seq(ymin(grid), ymax(grid), length.out=100)) ) plot(grid); points(points); di = dist2point(grid, points, parallel=TRUE, maxram = 0.5, nclus = 4, dist.method='Haversine') plot(di) points(points) ```

rsh249/rasterExtras documentation built on June 7, 2019, 7:38 a.m.