# GenerateDirectDistance: Converts a Points File into a Distance Matrix Using Direct... In VTrack: A Collection of Tools for the Analysis of Remote Acoustic Telemetry Data

## Description

This function calculates the straight line distance between a set of geographical coordinates and generates a matrix containing the distances between each of the points (i.e. receivers) minus the detection radius.

## Usage

 `1` ```GenerateDirectDistance(sPointsFile) ```

## Arguments

 `sPointsFile ` a dataframe containing the `LOCATION` (i.e. the STATIONNAME or the RECEIVERID), the coordinates and the detection `RADIUS` in meters. This should be in the format `LOCATION`, `LATITUDE`, `LONGITUDE`, `RADIUS`

## Value

a 2x2 matrix containing the pairwise direct `DISTANCE` between each `LOCATION` minus the detection `RADIUS`. Distances are returned in kilometers

## Author(s)

Ross Dwyer, Mathew Watts, Hamish Campbell

`GenerateCircuitousDistance`

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17``` ```# Load the points file data(PointsDirect_crocs) # Generate the direct distance matrix DirectDM <- GenerateDirectDistance(PointsDirect_crocs) # Now plot example of how direct distances between receivers were generated # In this example there are no structural boundary preventing an individual from # moving between receivers par(mfrow=c(1,1),las=1,bty="l") plot(PointsDirect_crocs\$LONGITUDE,PointsDirect_crocs\$LATITUDE,pch=10,cex=1, xlab="Longitude",ylab="Latitude") for(i in 1:length(PointsDirect_crocs\$LONGITUDE)) { lines(PointsDirect_crocs\$LONGITUDE[c(1,i)],PointsDirect_crocs\$LATITUDE[c(1,i)], lwd=0.3,col="grey",lty=3) } points(PointsDirect_crocs\$LONGITUDE,PointsDirect_crocs\$LATITUDE,pch=10,cex=1) ```

VTrack documentation built on May 2, 2019, 9:16 a.m.