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Hey guys,

I need to estimate the reaction rate from given data in excel. To answer this I set up the differential equations and appointed the given data (for the sake of convenience I briefly reduced the data set here). My first thought was that the most simple way to estimate the rate was to use ODE45, but since it doesn't works I assume I made a mistake somewhere.

This was the code I made:

function [dxdt] = data(t)

A = [0.98 0.97 0.95 0.92 0.90]';

B = [0.99 0.97 0.95 0.93 0.90]';

C = [0.01 0.03 0.07 0.11 0.16]';

A_rad = [0.01 0.02 0.02 0.03 0.03]';

B_rad = [0.01 0.02 0.02 0.03 0.03]';

dAdt = -1 .* A - 100 .* B_rad .* A + 1 .* (A_rad).^2;

dBdt = -100 .* A_rad .* B + 1000 .* B_rad .* C;

dCdt = (20000 ((A).^0.5) .* B) ./(100 + 1000 .*(C./A)); %This is the rate I want to estimate

%dBr_radical = 0; Since equal to zero it can be left out

%dH_radical = 0;

[dxdt] = [dAdt; dBdt; dCdt]

And next to call it:

init = [1 1 0 0 0];

tspan = [0 100];

[t,c] = ode45(@data, tspan, init, []);

plot(t,c)

Can someone help me improving my code?

Thanks in advance,

Kind regards,

Danny

darova
on 12 Sep 2019

You don't need to use ode45 since you already have table data

This is a result you want (as you wrote above):

dCdt = (20000 ((A).^0.5) .* B) ./(100 + 1000 .*(C./A)); %This is the rate I want to estimate

Star Strider
on 10 Sep 2019

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