Using a "For" loop using dates in a database

Hi, I imported in MatLab a database with the time series of five variables(let's call them A,B,...E) and the first column is the date vector(call it Date). I am trying to create a For loop that enables me to do some specific calculations every day. For simplicity, let's say that I want to compute daily A'*B. What would be the appropriate script to do this?

Thanks in advance

[Narges M]

Your question is not quite clear to me. Can you explain more?

[Colleen Howell]

I have a very similar question! I have an excel spreadsheet with lots of variables from 7 days.I have currently categorised the variables into bins such as levels of light exposure for the week as a whole but now I want to categorise the levels of light exposure for each date as well.

Can you help?

[Jan]

@Colleen Howell: Please open a new thread for your own question. It is not useful to attach a new question as a comment of an existing 5 year old thread.