Function [F,X] = mollier_F(T,gamma,pb,prop); returns the relative humidity F (with a value of 0...1) of air with a given air temperature T (in degrees C), given mass fractions gamma of dry air and water vapour (in kg per kg of the air mixture), repectively, and a given total pressure (or barometric pressure) pb (in Pa). If pb is empty or not given, the value of prop.pbstandard is used. The second input argument gamma contains two columns, for the dry air and water vapour fractions, respectively. The fourth input argument prop is a struct containing information on humid air properties, as returned by m-file mollier_humidairprop.m. This function is called, if the fourth input argument is not given. Internally, the function mollier_ps_xxxx() is called, as indicated by prop.ps_fun; see also the help text of that function. The mass fraction of water vapour, gamma(:,2) is converted to the absolute humidity X (in kg vapour per kg dry air) as follows: X = gamma(:,2) ./ (1 - gamma(:,2)); (c) 2026 fabien van mook 2026.08.20 release of this file within package "fvm-mollier" under GNU GPLv3+