fixBound: Fix the Boundary Points of a PolySet

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

View source: R/PBSmapping.r

Description

The ranges of a PolySet's X and Y columns define its boundary. This function fixes a PolySet's vertices by moving vertices near a boundary to the actual boundary.

Usage

1
fixBound (polys, tol)

Arguments

polys

PolySet to fix.

tol

vector (length 1 or 2) specifying a percentage of the ranges to use in defining near to a boundary. If tol has two elements, the first specifies the tolerance for the x-axis and the second the y-axis. If it has only one element, the function uses the same tolerance for both axes.

Details

When moving vertices to a boundary, the function moves them strictly horizontally or vertically, as appropriate.

Value

PolySet identical to the input, except for possible changes in the X and Y columns.

Author(s)

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

See Also

closePolys, fixPOS, isConvex, isIntersecting, PolySet.

Examples

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local(envir=.PBSmapEnv,expr={
  oldpar = par(no.readonly=TRUE)
  #--- set up a long horizontal and long vertical line to extend the plot's
  #--- limits, and then try fixing the bounds of a line in the top-left
  #--- corner and a line in the bottom-right corner
  polys <- data.frame(PID=c(1, 1, 2, 2,  3, 3, 4, 4),
    POS=c(1, 2, 1, 2,  1, 2, 1, 2),
    X = c(0, 10, 5, 5, 0.1, 4.9, 5.1, 9.9),
    Y = c(5, 5, 0, 10, 5.1, 9.9, 0.1, 4.9))
  polys <- fixBound(polys, tol=0.0100001)
  plotLines(polys)
  par(oldpar)
})

Example output

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

-----------------------------------------------------------
PBS Mapping 2.69.76 -- 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 2015-04-23
Pacific Biological Station, Nanaimo

All available PBS packages can be found at
http://code.google.com/p/pbs-software/

To see demos, type '.PBSfigs()'.
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PBSmapping documentation built on Jan. 15, 2021, 3:41 p.m.