massFrac2molFrac: convert from mass to mole fraction

Function converts a composition from mass fraction to mole fraction by solving a linear system of equations.

A simple function to easily convert compositions from mass fraction to mole fraction.

Inputs:

w = a vector containing the composition in mass fraction. Must sum to 1

elem = cell array of elements in the same order as they are listed in w

Ouput:

x = composition vector in mole fraction

Example

w =  [0.01, 0.1, 0.89];
elem = {'C','Cu','Fe'};
x = massFrac2molFrac(w,elem)

The output is

x = 
    0.0454
    0.0858
    0.8688