function to calculate analytic derivatives for computing d and t given p and s
function Helmholtz_ps extends Modelica.Icons.Function; input ThermalSeparation.Media.WaterBasedLiquid.BaseClasses.Common.HelmholtzDerivs f "dimensionless derivatives of Helmholtz function"; output ThermalSeparation.Media.WaterBasedLiquid.BaseClasses.Common.NewtonDerivatives_ps nderivs "derivatives for Newton iteration to compute d and t from p and s"; end Helmholtz_ps;