How would I perform a linear regression with a for loop on a set of data without using a GUI

So if I had a set of data X and Y of the same length

How would I do a linear regression with a for loop. I created a separate value xi where i have points of evaluation that spans the domain.

I would want to fit it to the curve Y= a*X+b and Y=A*X^b etc etc.

The equation I want it to run in the loop i've attached below. please help

[Jan]

It is hard to answer "etc etc". We need to know the details.

There are builtin command in Matlab to solve a linear regression. Why do you want a for loop?

[sunny blue]

I would need the two curves that I showed above and

y = a*(x/(x+b))

log(y) = a*log(a) + b

i would like to use a for loop for the linear one at the very least because that is what i have been told to use.

for arrays X and Y

x=0:1000;

for xi=1:length(x)
    
    it = find((X<x(xi)),1,'last')
    Y(xi)=Y(it)+(Y(it+1)-Y(it))/(X(it+1)-X(it)) * (x(xi)-X(it));
end

[Jan]

I'm not sure, what your question is.