Map Algebra Calculator
Raster calculator with a choice of engine: PCRaster map algebra, GDAL (numpy syntax) or GRASS r.mapcalc.
A raster calculator in the spirit of the QGIS Raster Calculator, with a choice of calculation engine:
- PCRaster: PCRaster map algebra, including terrain and hydrology (slope, lddcreate, accuflux, catchment), neighbourhood, zonal and spread operations.
- GDAL: numpy syntax as in gdal_calc (where, sqrt, logical_and, nanmean, ...).
- GRASS: r.mapcalc through QGIS Processing, including neighbour cells such as dem[-1, 0]; the translation to r.mapcalc syntax is shown while typing.
All engines share one Python-style syntax with and / or / not / xor, ranges (0.05 < slope < 0.2) and "x if condition else y". Scripts may span several lines with intermediate variables. Inputs are resampled onto a common output grid. The calculator is also available as Processing algorithms for the Toolbox, batch processing and the Model Designer, and a calculation can be exported as a standalone Processing script.
Dependencies: the GDAL engine works in every QGIS installation. The PCRaster engine requires PCRaster in the QGIS Python environment (not included; see the PCRaster Tools plugin or https://pcraster.geo.uu.nl for installation). The GRASS engine requires the GRASS provider of QGIS Processing (included in most QGIS installations). Engines that are not available are disabled with an explanation.