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I want to make the cells which values "1" to null in QGIS with Grass or Saga tools (exactly Saga).

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up vote 3 down vote accepted

Thanks to Volker Wichmann from SAGA GIS forums. If you want to change the cell values to null you can use Saga reclassify grid values from Sextante. Enter the -99999 which will be null on the option for new values for other values. Saga accepts -99999 value as NoData.

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please accept your own answer then. – Curlew May 12 '13 at 12:15

In GRASS GIS (hence, in QGIS via GRASS toolbox or Sextante-GRASS plugin), use r.null to set selected values to NULL. Any cell value may be turned into NULL.

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Old, but for anyone else who runs into this, r.null is not yet running on Sextante. – Nat Jul 17 '13 at 20:47

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