# 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(expand.grid(x = 4:6, y = seq(1, 7, 1.5)), z = rnorm(15, 3, 0.01)) # If I just wanted points, I would do the following: plot(df1[, 1:2], xlim = c(0, 7), ylim = c(0, 8), type = "n") points(df1, col = "blue") points(df2, col = "red") points(df3, col = "grey") # If the grids had equal spacing, the following would # work (in this case it doesn't): library(sp) df <- rbind(df1, df2, df3) coordinates(df) <- ~x+y gridded(df) <- TRUE spplot(df) # I had hoped that I could do something like: coordinates(df1) <- ~x+y gridded(df1) <- TRUE coordinates(df2) <- ~x+y gridded(df2) <- TRUE coordinates(df3) <- ~x+y gridded(df3) <- TRUE spplot(df1, xlim = c(0, 7), ylim = c(0, 8)) spplot(df2, add = TRUE) spplot(df3, add = TRUE) # but that doesn't work, so I tried: spplot(xlim = c(0, 6), ylim = c(0, 7), panel = function(x, y, subscripts, . . .) { panel.spplot(df1), panel.spplot(df2), panel.spplot(df3) } ) # which doesn't work either. # Is there any way round this? Regards, Mikkel Grum Genetic Diversity International Plant Genetic Resources Institute _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo