viamaris: calculate pairwise oceanic distances among sampling locations

Description Usage Arguments Value Author(s) Examples

Description

calculate pairwise oceanic distances among sampling locations

Usage

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viamaris(sampleXY, extent.buffer = NULL, resolution = NULL,
  EPSG = NULL)

Arguments

sampleXY

- a data frame with three columns: ID, X and Y (in decimal degrees)

extent.buffer

(optional) number of degrees to extend raster around your samples, default = 0.5 (you may need to increase this to allow navigation around land masses that extend beyond the extent of your samples)

resolution

(optional) the size of the raster, default = 1500 (1500 X 1500) (caution, increasing this too much will consume lots of RAM, without much benefit in accuracy)

EPSG

(optional) the coordinate reference system of your coordinates, default = 4326 (WGS84)

Value

distmat a list object containing the function call, distance matrix, and spatial objects you can use for plotting (original coordinates, adjusted coordinates (if used) and study area raster)

distmat.csv a pairwise matrix of distances (Km) between sampling sites

XY.kml a .kml file of the original coordinates that you can view in google earth

XY.kml a .kml file of the adjusted coordinates that you can view in google earth

Author(s)

Chris Brauer

Examples

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 ## set directory for results to be written
 setwd("path/to/working/directory")

 # load example coordinate file
 data(Tursiops.XY)

 # run analysis
 dist.mat <- viamaris(Tursiops.XY, extent.buffer = 5)

pygmyperch/melfuR documentation built on Oct. 10, 2020, 1:23 p.m.