tpeqd function

Two point equidistant and tilted perspective projections

Defines map projection

tpeqd(x, offset=c(0,0), axis='enu')
tpers(x,  hKm = 100*1000, tilt = -10,   azi, offset=c(0,0), axis='enu')

Arguments

• x: A SpatialPoints* object of length 2 or a matrix with two columns.
• hKm: Height veiwing the Earth from
• tilt: Viewing angle
• azi: Azimuth, defaults to direction of first two points in x
• offset: 2 coordinates to define the origin
• axis: defaults to east, north, up. 'swu' would rotateo 90 degrees

Details

A coordinate reference system is returned

Returns

Caracther string representing a crs.

References

https://en.wikipedia.org/wiki/Two-point_equidistant_projection

https://proj.org/operations/projections/tpers.html

See Also

crs,project

Examples

data('worldMap');worldMap=unwrap(worldMap)

thepoints = vect(rbind(cbind(150, -40), cbind(-70,-40)), crs=crsLL)
crsOne = tpeqd(thepoints)
worldMapTrans = wrapPoly(worldMap, crsOne)

oldpar=map.new(crsOne, col='lightblue')
plot(worldMapTrans, add=TRUE, col='grey')
points(project(thepoints, crsOne), col='red')
gridlinesWrap(crsOne, col='orange')


thepoints = vect(rbind(cbind(-40, 65), cbind(139,35)), crs=crsLL)
crsTwo = tpeqd(thepoints)

map.new(crsTwo, col='lightblue')
plot(wrapPoly(worldMap, crsTwo), add=TRUE, col='grey')
points(project(thepoints, crsTwo), col='red')
gridlinesWrap(crsTwo, col='orange')

par(oldpar)