I'm using the (awesome!) processing toolbox in QGIS 2.0 to reclassify some NoData values in a raster from -9999 to 0, but at some point in the process there's an offset of about 0.2 degrees being introduced to the output layer.
I'm using the "Reclassify (Simple)" tool (I believe it's part of SAGA), with some pretty basic parameters:
. . . and where the input raster was situated correctly in comparison to this hex grid:
. . . the output raster is bumped southeast by two hex cells, or about 0.2 degrees:
The input origin is -180, 83.623 . . . but the output origin is -179.05,83.05. Normally I would assume this is the result of a faulty WGS84 conversion, but the input, output and project are all EPSG:4326.
Where is this origin offset coming from, and is it worth filing a SAGA ticket or is it just something I overlooked?
Update The process log indicates a transformation is performed on the input origin:
Transformation x' = -179.999989 + x * 0.100000 + y * 0.000000 Transformation y' = 83.623125 + x * 0.000000 + y * -0.100000
and then a few lines later the new parameters show up, now incorrect:
Grid system: 0.1; 3600x 1735y; -179.949989x -89.826875y