Optimizing function fit function in Matlab using reformulation and extra error

I am trying to increase the speed of the functions I have implemented so that I can speed up the process. I have datasets in multiple files and of gigantic size. I am trying to find the pattern and hence it will definitely look more time consuming. With the assumption of little errors, what is the chance of minfunc function helping me in this regard? Are there any other functions in Matlab which helps in optimizing already optimized code? Thank you for your help.