[R-sig-Geo] Recs for R tools that subset/tile raster bricks?

[Michael Sumner]

Do also see the raster vignettes, there is one on performance and using
line- or block- based chunks for large jobs.

Cheers, Mike

On Thu, 25 May 2017, 08:32 Michael Sumner <mdsumner at gmail.com> wrote:

> Try crop() (or more abstractly extract(raster, cells) once you've
> determined which cells x-y are needed).
>
> Getting the most efficient way to do this depends on the source of the
> brick. It's not possible to know without knowing details on your setup. The
> file format, method of creation and dimensions of the brick and sizes of
> your subset query can all affect the best ways to go.
>
> Happy to help but it might take a bit of conversation to figure out what's
> best. If you can share the output of print on the brick anf the extent of a
> subset that is a good start.
>
> Cheers, Mike
>
> On Thu, 25 May 2017, 05:50 Megan Maloney <maloneymc at appstate.edu> wrote:
>
>> Hello all,
>>
>> Does anyone know of a good R tool to subset/tile raster bricks?
>>
>> I'd like to break a raster brick into smaller pieces to process. I'm
>> finding functions to subset or tile a single raster layer, but not for
>> multi-layer raster bricks.
>>
>> The brick input is hyperspectral flightlines - very large, 1 m^2
>> resampling
>> covering a watershed, 340 layers. My code currently takes in a raster
>> brick, extracts values per cell, applies beta coefficients, and outputs a
>> nitrogen value to a raster.
>>
>> I don't need the subsets/tiles to be a particular size or number, just
>> smaller. I was warned against dropping a whole flightline into R. I'm new
>> to
>> R, so I'm not sure what limitations I'm running into except processing
>> time.
>> All advice is welcome.
>>
>> Thank you very much for your help.
>> Megan
>>
>>         [[alternative HTML version deleted]]
>>
>> _______________________________________________
>> R-sig-Geo mailing list
>> R-sig-Geo at r-project.org
>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>
> --
> Dr. Michael Sumner
> Software and Database Engineer
> Australian Antarctic Division
> 203 Channel Highway
> Kingston Tasmania 7050 Australia
>
> --
Dr. Michael Sumner
Software and Database Engineer
Australian Antarctic Division
203 Channel Highway
Kingston Tasmania 7050 Australia

	[[alternative HTML version deleted]]