Displaying symbolic function with decimal number instead of fractional coefficients

The following code outputs a symbolic function with fractional coefficients, but I want it to display the coefficients as floating point numbers or doubles. I tried using fprintf but no format specifier I tried worked. Can someone tell me how the coefficients can be formatted?

a = [1.33 2.455 3.32 4];
syms x
f = [x,x^3,x,x^3].';
a*f

Answer 1

[John D'Errico]

Just use vpa.

help vpa

[Aleem Andrew]

Thanks for your answer