Fitting exponential curve in data

Question

gps 2021-6-6

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链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/849380-fitting-exponential-curve-in-data

评论： Matt J 2021-6-7

data.txt

I have a txt file with data corresponding to the number of atoms trapped as a function of time. How can I create a function (in a separate file) with

EDecay(t,τ,A,B) = A*exp(-t/τ)+B and then use the function fit to fit the data, using certain starting points? And then how can I deduce the lifetime τ?

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Answer 1

Matt J 2021-6-6

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/849380-fitting-exponential-curve-in-data#answer_718315

在 MATLAB Online 中打开

data.mat

A more efficient and direct way would be to use fminspleas (Download)

load data

funlist={@(tau,t)exp(-t/tau),1};

idx=tdata>0;

[tau,AB]=fminspleas(funlist,1,tdata(idx),ydata(idx));

tau,

tau = 3.0246

A=AB(1),

A = 9.8728e+05

B=AB(2)

B = 2.5888e+04

fn=@(t) A*funlist{1}(tau,t)+B;

plot(tdata,ydata,'o', tdata, fn(tdata));

xlabel 't';

ylabel 'EDecay';

ylim([0,2*max(ydata)])

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gps 2021-6-6

编辑：gps 2021-6-6

@Matt J thank you very much, this method does work, but would it also be possible to see how this can be achieved by creating a separate file with the function EDecay and using the fit function?