How to integrate this function using ode23?

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Anshuman S 2020-3-14

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/510825-how-to-integrate-this-function-using-ode23

评论： Ameer Hamza 2020-3-14

采纳的回答： Ameer Hamza

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The given function is as follows:

I've written the following code:

clc
clear all
tspan = [0 10];
y0 = 0;
%[t,y] = ode23(@(t,y) 2*t, tspan, y0);
Minc =  67;
Mp = 12;
dfe = 7200;
din = 4040;
Dp = 5e-5;
Cl = 0.045;
Cleq = 0.005;
z = (Minc/(100*Mp))*(dfe/din)*Dp*(Cl - Cleq) ;
disp( z)
[t,y] = ode23(@(t,y) (1/y)*(Minc/(100*Mp))*(dfe/din)*Dp*(Cl - Cleq), tspan, y0);
plot(t,y,'-o');

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Anshuman S 2020-3-14

But why tspan = [0.5 10], why not start from 0

tspan = [0 10]

Ameer Hamza 2020-3-14

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I was trying different values and this is the one I pasted here. This following one works too

tspan = [1e-308 10];

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采纳的回答

Ameer Hamza 2020-3-14

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/510825-how-to-integrate-this-function-using-ode23#answer_420100

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Although I couldn't figure out the actual cause of this issue, the error is caused by setting the initial condition to zero. It can be resolved by giving a tiny value to the initial condition. For example,

y0 = 1e-308; % minimum possible exponent for double