[R-sig-Geo] selecting n smallest values from a Raster

[Marcio Pupin Mello]

Great!
	I was trying "order(my.r)" instead of "order(my.r[])".
	Thank you Roman!
	Cheers,

Marcio
www.dsr.inpe.br/~mello


On 11/11/2013 11:15, Roman Luštrik wrote:
> Something like this?
>
> library(raster)
>
> my.r <- raster(nrow = 10, ncol = 10)
> my.r[] <- runif(ncell(my.r))
> plot(my.r)
>
> cell.numbers <- order(my.r[])
> cell.numbers[1:10]
>   [1]  32  33  81  12  28  98 100  34  69   2
> xyFromCell(my.r, cell.numbers[1:10])
>           x   y
>   [1,] -126  27
>   [2,]  -90  27
>   [3,] -162 -63
>   [4,] -126  63
>   [5,]   90  45
>   [6,]   90 -81
>   [7,]  162 -81
>   [8,]  -54  27
>   [9,]  126 -27
> [10,] -126  81
>
> points(xyFromCell(my.r, cell.numbers[1:10]))
>
> Cheers,
> Roman
>
>
>
>
> On Mon, Nov 11, 2013 at 2:05 PM, Marcio Pupin Mello <mello at ieee.org> wrote:
>
>> Dear list,
>>          I have a RasterLayer (raster package) and want to select "n"
>> smallest values from it (values and coordinates). I figured out that the
>> which.min function in the raster package give me the coordinate of the
>> smallest value. But how could I get the 10 smallest values?
>>          I'm using last version of R for Windows and all the packages.
>>          Thanks in advance,
>> --
>> Marcio
>> www.dsr.inpe.br/~mello
>>
>> _______________________________________________
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>> R-sig-Geo at r-project.org
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>>
>
>
>

-- 
Marcio
www.dsr.inpe.br/~mello