Suppose I have the following MATLAB code. syms a b c1 c2c1 = a + b + pi*bc2 = a + b + 0.5*bThen c1 gets evaluated to a + b + pi*b and c2 to a + (3*b)/2However, I need MATLAB to calculate double-precision values for the coefficients for a and b and not just symbolic expressions. How do I do this? e.g. I want c1 to be evaluated as a + 4.1416*b and c2 as a + 1.5*b.Also, suppose I am interested in doing arithmetic like c1*c2, c1*5, I would like the coefficients of a and b to evaluated as numbers. How should I do this? 
Simple substitutions using symbolic computing in MATLAB
matlab;symbolic computation