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

[Bacou, Melanie]

Sorry I meant reproject using nearest neighbor:

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

On 8/28/2016 2:37 AM, Bacou, Melanie wrote:
> 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)
>>      >
>>      >       [[alternative HTML version deleted]]
>>      >
>>      >
>>      >
>>      > _______________________________________________
>>      > R-sig-Geo mailing list
>>      > R-sig-Geo at r-project.org <mailto:R-sig-Geo at r-project.org>
>>      > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>      <https://stat.ethz.ch/mailman/listinfo/r-sig-geo>
>>
>>
>>              [[alternative HTML version deleted]]
>>
>>      _______________________________________________
>>      R-sig-Geo mailing list
>>      R-sig-Geo at r-project.org <mailto:R-sig-Geo at r-project.org>
>>      https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>      <https://stat.ethz.ch/mailman/listinfo/r-sig-geo>
>>
>>
>
> 	[[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