https://github.com/cran/fields
Tip revision: 04279c16ce718b82025aae97f6fcd30ba3a8b1c5 authored by Doug Nychka on 05 September 2011, 20:18:33 UTC
version 6.6
version 6.6
Tip revision: 04279c1
add.image.R
# fields, Tools for spatial data
# Copyright 2004-2011, Institute for Mathematics Applied Geosciences
# University Corporation for Atmospheric Research
# Licensed under the GPL -- www.gpl.org/licenses/gpl.html
"add.image" <- function(xpos, ypos, z, adj.x = 0.5,
adj.y = 0.5, image.width = 0.15, image.height = NULL, col = tim.colors(256),
...) {
m <- nrow(z)
n <- ncol(z)
ucord <- par()$usr
pin <- par()$pin
# if height is missing scale according to width assuming pixels are
# square.
if (is.null(image.height)) {
image.height <- (n/m) * image.width
}
# find grid spacing in user coordinates.
dy <- image.width * (ucord[4] - ucord[3])
dx <- image.height * pin[2] * (ucord[2] - ucord[1])/(pin[1])
#
# dx and dy should have the correct ratio given different different scales
# and also different aspects to the plot window
#
# find grid to put image in right place.
xs <- seq(0, dx, , m + 1) + xpos - adj.x * dx
ys <- seq(0, dy, , n + 1) + ypos - adj.y * dy
image(xs, ys, z, add = TRUE, col = col, ...)
}