data fitting to equation

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Sudhir Rai 2020-8-20

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评论： Walter Roberson 2023-1-10

@Matt J,@Walter Roberson

I have data for time(t) and pressure (p).

I want to fit these data to equation

I have done simple calcualtion and fittings in matlab. plese suggest how to fit data.

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Sudhir Rai 2023-1-10

d is constant that is length of diffusion . range of C_1, c_2 :

c_1 =1e-13 to 1e-17 and c_2=1e-9 to 1e-11 approximatly.

d is ~ 1e-4

Sudhir Rai 2023-1-10

t is time which could go upto 2000 s

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Just Manuel 2021-2-24

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在 MATLAB Online 中打开

Refer to this answer from Star Strider:

https://ch.mathworks.com/matlabcentral/answers/126146-curve-fitting-without-the-toolbox

You can fit any function using simple least squares regression. Just formulate your function (i guess you have already done that) in matlab, then make a cost function (least squares) and use fminsearch to optimize parameters c1 and c2

P = @(c, t) ... % your function
cost = @(c) sum((P(c,t) - p).^2);
% guess initial parameters
c_guess = [1 1]; 
% use fminsearch
c = fminsearch(cost, guess);