How does the regress function work in Matlab?

Hi!

Just wondering if anyone knows the theory behind how matlab computes the beta matrix?

Here is some example code:

x1 = pure_time;
x2 = pure_temp;
y = strength;
X = [ones(size(x1)) x1 x2 x1.*x2];
b = regress(y,X);
mod_strength = b(1) + (b(2)*x1) + (b(3)*x2) + (b(4)*x1.*x2);

What is Matlab doing to get b(1), b(2), b(3) and b(4) values?

Thanks! :)

[dpb]

Simply solving the OLS equations for the model given by the design matrix X

A introductory explanation is at https://towardsdatascience.com/linear-regression-understanding-the-theory-7e53ac2831b5

[Sophie Chumas]

Thanks!! This article is great.