function der_humidityRatio_xi extends TILMedia.BaseClasses.PartialGasObjectFunction; input SI.MassFraction[:] xi "Mass fractions of the first nc-1 components"; input TILMedia.Internals.TILMediaExternalObject gasPointer; input Real der_xi[:] "Mass fraction"; output Real der_humRatio "Content of condensing component aka humidity ratio"; end der_humidityRatio_xi;