[R-sig-Geo] How to resample a map using the statistical mode of class to fill the new pixel

[Bacou, Melanie]

Isaque,
If your LandScan raster is at 30m resolution, then best might be to 
`aggregate()` to as close as 250m (e.g. using `fact=8` or `fact=9` and 
`fun=modal`), and then use `projectRaster()`:

projectRaster(from, to, method="bilinear")

Others might have better ideas.
--Mel.


On 8/26/2016 10:43 PM, Tom Philippi wrote:
> Mel's answer is complete if you are aggregating to an integer multiple 
> of grid cells: if your tree cover was 5, 10, 25, 50, 125, etc., m 
> pixels.  If you are unlucky enough to have your tree cover in 15 or 
> 30m pixels, you may need to disaggregate to greatest common factor (5 
> or 10m) cells first, then aggregate up to 250m MODIS.  With mode on 
> categorical data, that should still give you your expected results; 
> with continuous raster values and other functions, it might not be 
> appropriate.
>
> Tom 2
>
>
> On Fri, Aug 26, 2016 at 7:28 PM, Bacou, Melanie <mel at mbacou.com 
> <mailto:mel at mbacou.com>> wrote:
>
>     Isaque, check this thread on StackExchange:
>     http://gis.stackexchange.com/questions/177423/r-aggregate-raster-with-mode-function-how-does-it-work
>     <http://gis.stackexchange.com/questions/177423/r-aggregate-raster-with-mode-function-how-does-it-work>
>
>     --Mel.
>
>
>     On 8/26/2016 10:07 PM, Isaque Daniel wrote:
>     > Hi dear all,
>     >
>     >
>     > I need to resample a tree cover map create by Landsat imagery to
>     the MODIS 250 meters.
>     >
>     > If I use the resample function of raster package, it will
>     compute the value based on bilinear or ngb, in this condition the
>     new class map will not answer my expectations.
>     >
>     >
>     > I loking for a way of resample using the statistical mode to
>     define the value of the pixel of the new map.
>     >
>     >
>     > Some tip about this?
>     >
>     > Thanks
>     > Isaque
>     >
>     >
>     >
>     >
>     ------------------------------------------------------------------------------------------------------------------
>     > Agronomist engineer
>     > Master in Remote Sensing - National  Institute for Space
>     Research (INPE) - Brazil
>     > PHD Student in Transport - Bras�lia University (UNB)
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