[R-sig-Geo] raster package and tiling schemes

[Alex Mandel]

On 01/19/2016 09:22 PM, Michael Sumner wrote:
> Hi there, does raster or any related package have any built-in  schemes
> that allow for easy management of tiles?
> 
> Raster itself provides a very powerful platform for building such a scheme,
> since we can reasonably easily reclassify analogous RasterLayers at
> different resolutions, and map cell values from one raster to another -
> being careful with tile overlaps and alignment of course.
> 
> Anyone working on such a thing already, or got any grand plans?
> 
> I know rgdal and friends provide access to the GDAL tools in various ways,
> but I want something in R only.
> 
> Cheers, Mike
> 


What's the goal of tiling? And when you say tiles do you mean multiple
zoom levels like web tiles, or more a raster catalog like a VRT of
multiple rasters next to each other?

If you mean zoom levels, things like pyramids in tiffs are local
equivalent but that's only for viewing data, not really useful for analysis.

If you mean things that are adjacent to each other, I would assume that
if they aren't all the same resolution/scale then you need to go to the
lowest common denominator and resample everything to that to get a
seamless data set. In this case the Raster merge and mosaic functions.
Though if you want to keep the files in pieces, save them all out into
the same resolution/scale, clipped to no longer have overlap, and
gdal_buildvrt.

Or am I missing the point?

-Alex