[R-sig-Geo] Performance of raster package

[Carsten Neumann]

  Am 24.05.2011 10:17, schrieb Luca Morandini:
> Folks,
>
> I have played a bit with the R "raster" package, and found it has an 
> impressive list of features; however, its performance seems to be less 
> than optimal when confronted with sizeable rasters (say, a 250MB 
> GeoTIFF): a focal statistics that took less than a minute in GRASS, 
> took 7 hours or so in R.
>
> Is there anything I could do to speed it up (I already tried readAll 
> before invoking the focal statistic function) ?
>
> Regards,
>
> Luca Morandini
> http://www.lucamorandini.it
>
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Dear all,

I discovered such performance problems concerning computation time, too. 
Using the function rasterToPolygons() for a 30Mb, 1Byte integer GeoTiff 
took 10 times longer than using a common GIS software. Why is that the 
case? I had to change to other R implementet GIS functionallity like in 
the package RSAGA. When posible reading data into memory will also 
accelerate processing time.

Best regards

Carsten