Edzer, Thanks for your help. For some reason I had it
that you couldn't use add = TRUE with image(). I
thought I had tested it. It will work for me.
Using the grid centres to create a new grid with
levelplot would in some cases give me problems with
grid sizes (many more grids cells).
I'll have a
Mikkel, I've looked at it for a while but can't see an easy
solution to this, apart from using
image(df1, xlim = c(0, 6), ylim = c(0, 7))
image(df2, add = T)
image(df3, add = T)
spplot basically wraps levelplot for grids, and I don't see an
easy way out using that for multiple grids with differen
# Is there a way to plot contiguous spatial grids on
# the same plot, even when the grids have
# unequal spacing? An example would be:
df1 <- data.frame(expand.grid(x = 1:3, y = 1:4), z =
rnorm(12, 1, 0.01))
df2 <- data.frame(expand.grid(x = 1:3, y = 5:7), z =
rnorm(9, 2, 0.01))
df3 <- data.frame
