I am using the raster calculator in QGIS 2.18.11, and I want to find the equation/input that went in the "raster calculator expression" box for rasters that have already been created with the raster calculator.
Unfortunately QGIS 2.18 Raster calculator does not keep history of expressions or input parameters.
However, if we run Raster calculator in QGIS 3.0 from
Processing Toolbox | QGIS Raster analysis, there is a
Log window (available until we close the session).
We can also Save our own expressions for future use.