I am working on CH4/air combustion study using Open Foam, i am having doubt in ploting graph of mixture fraction versus Chemical Explosive Mode Analysis(CEMA). i need to extract data for eigen value for the Chemical Explosive Mode Analysis. Can tell me how to calculate CEMA ? for this one screen shot of reference paper is attached.I gone through reference papers of CEMA but i did not get solution to how to calculate eigen values for burnt mixture.