PBSmapping (version 2.73.4)

convLP: Convert Polylines into a Polygon

Description

Convert two polylines into a polygon.

Usage

convLP (polyA, polyB, reverse = TRUE)

Value

PolySet with a single PID that is the same as

polyA. The result contains all the vertices in polyA and

polyB. It has the same projection and zone

attributes as those in the input PolySets. If an input PolySet's attributes equal NULL, the function uses the other PolySet's. If the PolySet attributes conflict, the result's attribute equals NULL.

Arguments

polyA

PolySet containing a polyline.

polyB

PolySet containing a polyline.

reverse

Boolean value; if TRUE, reverse polyB's vertices.

Author

Nicholas M. Boers, Staff Software Engineer
Jobber, Edmonton AB
Last modified Rd: 2013-04-10

Details

The resulting PolySet contains all the vertices from polyA in their original order. If reverse = TRUE, this function appends the vertices from polyB in the reverse order (nrow(polyB):1). Otherwise, it appends them in their original order. The PID column equals the PID of polyA. No SID column appears in the result. The resulting polygon is an exterior boundary.

See Also

addLines, appendPolys, closePolys, convCP, joinPolys, plotLines.

Examples

local(envir=.PBSmapEnv,expr={
  oldpar = par(no.readonly=TRUE)
  #--- create two polylines
  polyline1 <- data.frame(PID=rep(1,2),POS=1:2,X=c(1,4),Y=c(1,4))
  polyline2 <- data.frame(PID=rep(1,2),POS=1:2,X=c(2,5),Y=c(1,4))
  #--- create two plots to demonstrate the effect of `reverse'
  par(mfrow=c(2, 1))
  plotPolys(convLP(polyline1, polyline2, reverse=TRUE), col=2)
  plotPolys(convLP(polyline1, polyline2, reverse=FALSE), col=3)
  par(oldpar)
})