IDW Interpolation

Mar 22, 2014 at 11:17 PM
I'm trying to interpolate rain data from some stations. I have the accumulated value for each point and need to create a grid for a specific area.
As the goal of my project is to create a plugin for MapWindow, I'm using the "Imports MapWinGeoProc.Interpolation" declaration to import the interpolation procedures.

The IDW method is an option, but the simple code below is not working (using Visual Studio 2010 and MapWindow 4.8.8):

Imports MapWinGeoProc.Interpolation
IDW("c:\temp\points.shp", 3, "c:\temp\idw_pnts.asc")

The folowing error is generated in the debug:
"startIndex cannot be larger than length of string".

Points.shp is point shapefile that has the rain data in the field of index 3.

Any help? Is IDW interpolation or MapWinGeoProc library no longer supported?
Dec 8, 2014 at 6:37 AM
Do you still have issues with this?
The interpolation in the MapWinGeoProc library is indeed not very stable nor very fast.

It might be better to use gdal_grid.exe (

I've added this to the wishlist, so we can implement gdal_grid in MapWinGIS.