calcConvexHull: Calculate the Convex Hull for a Set of Points
In PBSmapping: Mapping Fisheries Data and Spatial Analysis Tools

Description Usage Arguments Details Value Author(s) See Also Examples

Calculate the convex hull for a set of points.

1	calcConvexHull (xydata, keepExtra=FALSE)

`xydata`	a data frame with columns `X` and `Y` containing spatial coordinates.
`keepExtra`	logical: if `TRUE`, retain any additional columns from the input data frame `xydata`.

This routine uses the function chull() in the package grDevices. By default, it ignores all columns other than X and Y; however, the user can choose to retain additional columns in xydata by specifying keepExtra=TRUE.

PolySet with columns PID, POS, X, Y, and additional columns in xydata if keepExtra=TRUE.

Nicholas M. Boers, Associate Professor – Computer Science
MacEwan University, Edmonton AB
Last modified Rd: 2013-04-10

addPoints, addPolys, calcArea, calcCentroid, calcMidRange, calcSummary, locateEvents, plotMap, plotPoints, plotPolys.

local(envir=.PBSmapEnv,expr={
  oldpar = par(no.readonly=TRUE)
  data(surveyData,envir=.PBSmapEnv)
  #--- plot the convex hull, and then plot the points
  plotMap(calcConvexHull(surveyData),col="moccasin")
  addPoints(surveyData,col="blue",pch=17,cex=.6)
  par(oldpar)
})

sh: 1: cannot create /dev/null: Permission denied

-----------------------------------------------------------
PBS Mapping 2.70.4 -- Copyright (C) 2003-2017 Fisheries and Oceans Canada

PBS Mapping comes with ABSOLUTELY NO WARRANTY;
for details see the file COPYING.
This is free software, and you are welcome to redistribute
it under certain conditions, as outlined in the above file.

A complete user guide 'PBSmapping-UG.pdf' is located at 
/usr/lib/R/site-library/PBSmapping/doc/PBSmapping-UG.pdf

Packaged on 2017-06-28
Pacific Biological Station, Nanaimo

All available PBS packages can be found at
https://github.com/pbs-software

To see demos, type '.PBSfigs()'.
-----------------------------------------------------------