summary: how to use GSIF::make.3Dgrid for general-purpose "reboxing," or 3D interpolation? Particularly, can one use varying vertical bounds rather than the same "standard depths" for both input and output?
details: Apologies if the following questions reveal a profound ignorance of spatiality or geostatistics (which I'm learning slowly and "on-the-fly") and if I'm missing something simple regarding GSIF; unfortunately the tutorial http://gsif.r-forge.r-project.org/tutorial_eberg.php seems to require more geostatistical background than I currently have. https://stat.ethz.ch/pipermail/r-sig-geo/2012-November/016573.html >>> [I seek to] incorporate N2O emissions inventories (EIs), initial >>> conditions (ICs), and boundary conditions (BCs) from relatively >>> coarse-scaled global inventories (with horizontal grids on the order >>> of degrees lon-lat) into a [finer-scaled] regional atmospheric model >>> (12-km LCC horizontal). The [EIs] are [surface/2D] and I now know >>> how to "regrid," or interpolate from one 2D grid to another. >>> However the model and [its] IC/BCs are 3D[, and] have [both] >>> different vertical layering (i.e., [number and height of layers]) >>> [and] different horizontal grids. I'd like to know: is there R code >>> available that will "rebox," i.e., interpolate vertically as well as >>> horizontally? To further specify: my global IC/BC estimates mass concentration for each box/voxel in a regular, unprojected grid 1.875° x 2.5° x 56 levels. I want to "rebox" from global IC/BCs to model-ready IC/BCs, where the latter must estimate mass concentration over a regular grid that horizontally projects to LCC over North America at 12-km resolution, and which has 34 vertical levels. (Both the vertical and horizontal extents of the model-ready IC/BC are subsets of the global extents.) I can compute the sizes of the boxes, so I can compute the mass in each input box, and recompute the output concentrations, presuming I can learn how to rebox the masses. https://stat.ethz.ch/pipermail/r-sig-geo/2012-November/016578.HTML > I've produced some 3D interpolation examples in the experimental > package GSIF (under construction). You can actually create some kind > of voxels via the SpatialPixelsDataFrame class > http://gsif.r-forge.r-project.org/make.3Dgrid-method.html > and then predict at those locations. From http://gsif.r-forge.r-project.org/make.3Dgrid-method.html it appears one can provide as input * an unprojected SpatialPixelsDataFrame or RasterBrick * a PROJ.4 string defining the output CRS * a "list of standard depths" and get an output list of SpatialPixelsDataFrame's (one per standard depth). From the description, it seems like GSIF::make.3Dgrid is doing a 2D regridding at each standard depth, such that the heights of the input box/voxels must match that of the output box/voxels. Is that correct? If not, how can one rebox from an input with one set of layer heights (or vertical bounds) to an output with another set of layer heights? Can `gdalwarp` do that, or is it (like, IIUC, raster::projectRaster) restricted to 2D? Your assistance is appreciated! Tom Roche <tom_ro...@pobox.com> _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo