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Last data update: 2014.03.03

R: Adds long-lat grid for projected data

gridlinesWrap

R Documentation

Adds long-lat grid for projected data

Description

long-lat grid lines are added to a map in the coordinate system specified, allowing for map projections wrapped differently from the 180 meridian.

Usage

gridlinesWrap(crs, 
		easts=seq(-180,180,by=60),
		norths=seq(-90,90,by=30),
		ndiscr=40, plotLines=TRUE, 
		plotLabels = TRUE, ...)

Arguments

`crs`	A `CRS` object, proj4 string, or an object from which a projection can be extracted with `proj4string(crs)`
`easts`	vector of longitudes
`norths`	vector of latitudes
`ndiscr`	number of intermediate points per line
`plotLines`	add lines to existing plot
`plotLabels`	add labels to existing plot
`...`	Additional arguments passed to `lines` or `text`, for example `lty=2`

Author(s)

Patrick Brown

Examples

## Not run: 
Npoints = 20
myPoints = SpatialPointsDataFrame(
	cbind(
	runif(Npoints, -15000000, 15000000), 
	runif(Npoints, -8000000, 8000000)), 
	data=data.frame(y1=c(NA, rnorm(Npoints-1)), 
	y2=c(sample(0:5, Npoints-1,replace=TRUE), NA)),
	proj4string=moll(c(-100,0))
)


plot(myPoints)
gridlinesWrap(myPoints, lty=3, col='red')

## End(Not run)