Calculates the derivative of the water content
function wDerPhi input Modelica.Units.SI.MassConcentration w; input Modelica.Units.SI.MassConcentration sorTabX[:]; input BuildingSystems.Types.RelativeHumidity sorTabY[:]; input Modelica.Units.SI.MassConcentration wF; input BuildingSystems.Types.RelativeHumidity phi; input BuildingSystems.Types.Porosity por; output Modelica.Units.SI.MassConcentration value; end wDerPhi;