Increase MATLAB precision without using vpa or sym

Is there any way to increase MATLAB's precision (E-16) without using vpa or sym? This is, without modifying the existing code?

Answer 1

[John D'Errico]

No.

Well, you could use my HPF toolbox, but that too would require mods to your code.

You cannot simply tell MATLAB to use a higher precision. Double precision is all you get. If you need more than that, then you need to use tools that can give you higher precision. Or learn to write code that does not need higher precision. That is the stuff of numerical analysis courses and textbooks, of much of applied mathematics.