Added dx (dQ) to read from data file if exists
Added dx (dQ) to read from data file if exists

SasView/sasview,lewisodriscoll/sasview,lewisodriscoll/sasview,SasView/sasview,lewisodriscoll/sasview,SasView/sasview,SasView/sasview,SasView/sasview,SasView/sasview,lewisodriscoll/sasview,lewisodriscoll/sasview