# convLP: Convert Polylines into a Polygon In PBSmapping: Mapping Fisheries Data and Spatial Analysis Tools

## Description

Convert two polylines into a polygon.

## Usage

 `1` ```convLP (polyA, polyB, reverse = TRUE) ```

## Arguments

 `polyA` PolySet containing a polyline. `polyB` PolySet containing a polyline. `reverse` Boolean value; if `TRUE`, reverse `polyB`'s vertices.

## 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.

## 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`.

## Author(s)

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

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

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11``` ```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) }) ```

### Example output

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

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A complete user guide 'PBSmapping-UG.pdf' is located at
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Packaged on 2017-06-28
Pacific Biological Station, Nanaimo

All available PBS packages can be found at
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To see demos, type '.PBSfigs()'.
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```

PBSmapping documentation built on Jan. 15, 2021, 3:41 p.m.