# How to find minimum and maximum of a fitted curve.??

30 visualizzazioni (ultimi 30 giorni)
Chris Martin il 29 Set 2014
Commentato: Jan Dabrowski il 30 Nov 2020
I have fitter my time series using fourier option of fit command, I want to know how to find the minimum and maximum of the fitted curve
##### 2 CommentiMostra NessunoNascondi Nessuno
Matt J il 29 Set 2014
Modificato: Matt J il 29 Set 2014
You have many open threads on your profile, many of which have had responses. You should consider closing some of them unless the answers given there really didn't help you. It's hard to imagine though, that so many answers were ineffective.
Chris Martin il 13 Nov 2014
Modificato: Chris Martin il 13 Nov 2014
If the answer is not suitable then what can I do..

Accedi per commentare.

### Risposta accettata

Matt J il 29 Set 2014
Modificato: Matt J il 29 Set 2014
My approach would be to,
1. Sample the curve finely (much higher sampling rate than the frequency of the fitted curve) and get approximate locations of the global max and min from the samples using the commands min() and max()
2. Refine the approximation from Step 1 using fzero. That is, use fzero to find where the derivative of the fitted curve is zero, using the points from Step 1 as the intial guesses.
##### 3 CommentiMostra 1 commento meno recenteNascondi 1 commento meno recente
Matt J il 30 Set 2014
Modificato: Matt J il 30 Set 2014
That's what my 2-step Answer told you how to do. Use feval in Step 1, or the other methods mentioned here,
to evaluate the curve at many points. When you have a vector of samples of hte curve, you can apply max() or min() to find approximate locations of the max and min. Then, in Step 2, you can refine with fzero, if you wish.
Jan Dabrowski il 30 Nov 2020
Thanks man, you helped me a lot!

Accedi per commentare.

### Categorie

Scopri di più su Get Started with Curve Fitting Toolbox in Help Center e File Exchange

### Community Treasure Hunt

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

Start Hunting!

Translated by