Finding where a slope becomes linear

I recently took a class teaching Matlab and I'm trying to use it at my internship to find where our plotted data, using a vector of x and y data values, starts to become linear. I am trying to use a polyfit and then find the slope using the maximum slope and find the y value of where that begins. Can someone help me?

[Jan]

What is a vector of x and y data? What exactly is a linear slope? Are you looking for a zero curvature? How do you use the maximum slope to find the value where what begins?

Answer 1

[Jan]

I'm not sure about the question. Perhaps you are looking for this:

curvature = diff(diff(x));
find(curvature < 1e-6)

[Daniel Jednorozec]

Actually that did help me thank you. Sorry if I was so vague, the data was defined as two columns which I defined as x and y with respect to the axis they related to. But this answered my question.

[Jan]

Fine. See also the GRADIENT command.