Oblique Mercator, Cylindrical, and Mollweide projections

Description

Defines an appropriate Oblique Mercator, Oblique Cylindrical Equal Area, and Mollweide projections for a supplied Spatial object

Usage

	omerc(x, angle,  
	post=c('none', 'north', 'wide','tall'),
    preserve=NULL) 
    ocea(x, angle, flip=FALSE)
    moll(x=0, angle=NULL, flip=FALSE)

Arguments

Details

With omerc, an Oblique Mercator map projection is produced which warps the world onto a cylinder, with the north-south axis rotated by the specified angle. If angle is a vector, the optimal angle for reducing the size of the bounding box is returned.

If post = 'north', an inverse rotation will preserve the north direction at the origin.

If post = 'wide', an inverse rotation makes the smallest possible bounding box which is wider than tall.

If post = 'tall', the bounding box is taller than it is wide

If post is numeric, it specifies an angle for inverse rotation.

ocea produces an Oblique Cylindrical Equal Area projection and moll a Mollweide projections

Value

An object of class CRS.

References

http://www.remotesensing.org/geotiff/proj_list/oblique_mercator.html, http://en.wikipedia.org/wiki/Space-oblique_Mercator_projection

See Also

CRS,spTransform

Examples

omerc(c(10,50), angle=c(0,45,80))

data('netherlands')

if(require('rgdal', quietly=TRUE)){
nldUtm = spTransform(nldCities,
	omerc(nldCities, angle=0))
projection(nldUtm)

map.new(nldUtm)
text(nldUtm,labels=nldUtm$name)
scaleBar(nldUtm, 'topright')

nldRot = spTransform(nldCities,
omerc(nldCities, angle=seq(25,45,by=1))
)
projection(nldRot)

map.new(nldRot)
text(nldRot,labels=nldRot$name)
scaleBar(nldRot, 'topright')
insetMap(nldRot, 'bottomright',map=world)

if(require('rgeos', quietly=TRUE) & require('geosphere', quietly=TRUE)){
	nldMollCrs = moll(nldCities)
	nldMoll = spTransform(nldCities, nldMollCrs)
	map.new(nldMoll, buffer=2000)
	text(nldMoll,labels=nldMoll$name)
	scaleBar(nldMoll, 'topright')
	
	
}
}
## Not run: 

	nldOceaCrs = ocea(nldCities)
	nldOcea = spTransform(nldCities, nldOceaCrs)
	map.new(nldOcea, buffer=2000)
	text(nldOcea,labels=nldOcea$name)
	scaleBar(nldOcea, 'topright')

	map.new(nldCities)
	plot(nldTiles,add=TRUE)
	text(nldCities,labels=nldCities$name)

	tilesRot = openmap(nldRot)
	map.new(nldRot)
	plot(tilesRot,add=TRUE)
	text(nldRot,labels=nldRot$name)
	
	tilesUtm = openmap(nldUtm)
	map.new(nldUtm)
	plot(tilesUtm,add=TRUE)
	text(nldUtm,labels=nldUtm$name)


## End(Not run)

Results