Hello R users, I have numerical data sampled on two grids, each one shifted by 0.5 from the other.
For example: grid1 = expand.grid(x=0:3, y=0.5:2.5) grid2 = expand.grid(x=0.5:2.5, y=0:3) gridFinal = expand.grid(x=0.5:2.5, y=0.5:2.5) plot(gridFinal, xlim=c(0,3), ylim=c(0,3), col="black", pch=19) points(grid1, xlim=c(0,3), ylim=c(0,3), col="red", pch=19) points(grid2, xlim=c(0,3), ylim=c(0,3), col="blue", pch=19) I would like to interpolate the quantities on grid1 (red) and grid2 (blue) on the same grid (black). This scenario is very common in geophysical data and models. I only found: - functions in package akima which are designed for irregular grids - krigging in package fields, which also requires irregular spaced data - approx or spline which works in 1D and which I could apply line by line and column by column and use a mean of both estimates I am sure there are plenty of functions already available to do this but searching R-help and the packages site did not help. Pointer to a function/package would be highly appreciated. Eventually, the same scenario will occur in 3D so if the function is 3D capable it would be a plus (but I am sure the solution to this is generic enough to work in nD) Thank you in advance. JiHO --- http://jo.irisson.free.fr/ ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
