% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/bru.spatial.R
\name{spoly}
\alias{spoly}
\title{Convert a data.frame of boundary points into a SpatialPolgonsDataFrame}
\usage{
spoly(data, cols = colnames(data)[1:2], crs = CRS(as.character(NA)),
  to.crs = NULL)
}
\arguments{
\item{data}{A data.frame of points describing the boundary of the polygon}

\item{cols}{Column names of the x and y coordinates within the data}

\item{crs}{Coordinate reference system of the points}

\item{to.crs}{Coordinate reference system for the SpatialLines ouput.}
}
\value{
SpatialPolygonsDataFrame
}
\description{
A polygon can be described as a sequence of points defining the polygon's boundary.
When given such a sequence (anti clockwise!) this function creates a 
SpatialPolygonsDataFrame holding the polygon decribed. By default, the
first two columns of \code{data} are assumed to define the x and y coordinates
of the points. This behavior can ba changed using the \code{cols} parameter, which
points out the names of the columns holding the coordinates. The coordinate
reference system of the resulting spatial polygon can be set via the \code{crs}
paraemter. Posterior conversion to a different CRS is supported using the
\code{to.crs} parameter.
}
\examples{
\donttest{
# Create data frame of boundary points (anti clockwise!)
pts = data.frame(x = c(1,2,1.7,1.3),
                 y = c(1,1,2,2))

# Convert to SpatialPolygonsDataFrame
pol = spoly(pts, crs = CRS(as.character(NA)))

# Plot it!
ggplot() + gg(pol)
}
}
