Creates a new vector layer as a result of the union of a points layer with the interpolated value of one or more base background grid layer(s). This way, the new layer created will have a new column in the attribute table that reflects the interpolated value of the background grid.
interpolation method to use.
Options:
Default: 0
processing.runalg('saga:addgridvaluestopoints', shapes, grids, interpol, result)