清空筛选条件
清空筛选条件

I want to find the best coefficients for curve fitting for my experiment data

1 次查看（过去 30 天）
Misi
Misi 2022-7-18
评论： Misi 2022-7-18
Greetings
I have experiment data as you can see below, I want to find the curve with the formula of y=K0+K1exp(-t/Tau) which is fit to my experiments data.
I have 'y' and 't' from experiment and I am looking for the best values for K0, K1 and Tau.
the bellow is the graph of my experiment data

请先登录，再回答此问题。

采纳的回答

Image Analyst
Image Analyst 2022-7-18
You can use fitnlm if you have the stats toolbox. See attached demo and make changes as needed, like reading in your actual data, and renaming variables if you want.

更多回答（2 个）

Torsten
Torsten 2022-7-18
Try "lsqcurvefit".
  1 个评论
Misi
Misi 2022-7-18
编辑：Misi 2022-7-18
Thank you
I used the lsqcurve fit but it couldnot fit on my curve and the final asnwer was zero for all coeffiecient.
This what I recieved in command window
Initial point is a local minimum.
Optimization completed because the size of the gradient at the initial point
is less than the default value of the optimality tolerance.
<stopping criteria details>
a =
0
b =
0
c =
0

请先登录，再进行评论。

Torsten
Torsten 2022-7-18
Ran in:
Your code ?
Essential in your case is a good starting guess for the parameters.
Try the following code and take the coefficients as initial values for the optimization.
fun = @(K0,K1,tau,t) K0 + K1*exp(-t/tau);
t = 0:0.1:10;
K0 = 1e10;
K1 = 6.2e10;
tau = 4.5;
y = fun(K0,K1,tau,t);
plot(t,y)

类别

在 Help Center 和 File Exchange 中查找有关 Get Started with Curve Fitting Toolbox 的更多信息

标签

产品

Community Treasure Hunt

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

Start Hunting!

Translated by