parrows {autoimage}

Projected arrows function

Description

parrows takes pairs of coordinates and draws arrows between them, possibly after projection.

Usage

parrows(x0, y0, x1 = x0, y1 = y0, proj, ...)

Arguments

x0, y0

coordinates of points from which to draw.

x1, y1

coordinates of points to which to draw

proj

A character string indicating what projection should be used for the included x and y coordinates. The default is "none". The other valid choices correspond to the "projection" argument in the mapproject function, which is used for the projection.

...

Additional arguments passed to the arrows

Details

The mapproject function is used for projection.

See Also

arrows, mapproject, pimage

Examples

data(narccap)
# plot image using bonne projection (w/o grid lines)
pimage(lon, lat, tasmax[,,1], proj = "bonne",
       parameters = 40, paxes.args = list(grid = FALSE))
# load some data for larger U.S. cities
data(us.cities, package = "maps")
cityxy <- list(x = us.cities$long[1:5], y = us.cities$lat[1:5])
parrows(cityxy$x[1:4], cityxy$y[1:4], cityxy$x[2:5], cityxy$y[2:5], 
        proj = "bonne", col = "orange")