ess.beer.io.load.mcstas_source_position# ess.beer.io.load.mcstas_source_position()[source]# Return the source position used for analytical McStas frame unwrapping. Return type: Position[NXsource, TypeVar(RunType, ess.reduce.nexus.types.SampleRun (int), ess.powder.types.VanadiumRun (int), ess.powder.types.EmptyCanRun (int))]