Help with writing a function of Log-return and Volatility of a stock

Need some help about Writing a Matlab function that computes the 20days-historical mean of log-return and volatility of a stock. Formulas as below.

Thanks in advance. Im really stuck..

Answer 1

[Asvin Kumar]

I'm not sure what the terms in those expressions are. If you're new to MATLAB and would like to learn the basics, have a look at the free MATLAB Onramp course. That should get you up to speed on how to use some basic functions.

Roger has an answer on calculating log returns here. You could also look for any existing function from the Financial Toolbox that would satisy your use case.