mapasp: Calculate aspect ratio for plotting geographic maps; create...

Description Usage Arguments Value Note See Also

View source: R/mapasp.R

Description

Calculate aspect ratio for plotting geographic maps; create nice degree axis labels

Usage

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Arguments

data

object of class or extending Spatial

xlim

the xlim argument passed (or derived from bounding box)

ylim

the ylim argument passed (or derived from bounding box)

x

numeric; values at which tics and marks will be generated

Value

mapasp is used for the aspect argument in lattice plots and spplot;

let x = dy/dx, with dy and dx the y- and x-size of the map.

let s = 1/cos((My * pi)/180) with My the y coordinate of the middle of the map (the mean of ylim)

for latlong (longlat) data, mapasp returns s * x. for other data, mapasp returns "iso".

Note

the values for x are typically obtained from axTicks

See Also

levelplot in package lattice


sp documentation built on Jan. 13, 2021, 12:09 p.m.