Help with basic fitting

5 views (last 30 days)
aurc89
aurc89 on 23 Feb 2014
Commented: Image Analyst on 25 Sep 2018
Hello,I would like to fit a curve with a line and retrieve slope and intercept of this linear fit. Let x and y be the vectors which define the curve, which is already similar to a line; I plot x vs y, then from the plot window I select Tools --> Basic fitting --> Linear fit, then I press 'Show equation' so that from the expression y=mx + q I retrieve both the slope m and the intercept q. The problem is that I want to obtain immediatly m and q from the Matlab code, without doing it manually as discussed above. How can I do this ? Thanks

Accepted Answer

Mischa Kim
Mischa Kim on 23 Feb 2014
Edited: Mischa Kim on 23 Feb 2014
Try
[p,S] = polyfit(x,y,1)
The two elements of p are the coefficients m and q you are looking for.
  2 Comments
Andrea Gómez Montoya
Andrea Gómez Montoya on 25 Sep 2018
What is S on the answer?
Image Analyst
Image Analyst on 25 Sep 2018
It's explained in the help for polyfit().

Sign in to comment.

More Answers (1)

Image Analyst
Image Analyst on 23 Feb 2014
for what it's worth, I've attached a demo of polyfit.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!