[GIS] SAGA Inverse Distance Weighting in QGIS – How to Set Minimum Number of Points

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I am analyzing a postGIS point dataset in QGIS version 2.8.2, about 200k features total. To calculate weighted average values I am using the Inverse Distance Weighted interpolation technique. However, I am concerned that the "high" values I'm seeing in the outputs are the result of a handful of outlier values, not the basis of any meaningful spatial pattern.

Is there a way in the SAGA IDW plugin – or another IDW tool – to set a minimum number of points required for the raster surface to calculated the weighted averages, the same way it considers a maximum number of points?

Best Answer

The original SAGA IDW method does have a parameter for minimum number of points. But this parameter is not used in the QGIS version of the SAGA method.

As an alternative you could create a layer that contains only the points that have the minimum number of points within the search radius. Have a look at this answer for the code to make such a selection.

I hope this helps.

and here's hoping that Necromancer badge comes my way. ;-)

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