MATLAB Answers

How to calculate the rate using a given data set?

45 views (last 30 days)
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
  1 Comment
darova
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

Sign in to comment.

Accepted Answer

Star Strider
Star Strider on 10 Sep 2019
You are not coding your differential equations and data correctly. See for example: Parameter Estimation for a System of Differential Equations.
  13 Comments

Sign in to comment.

More Answers (0)

Community Treasure Hunt

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

Start Hunting!

Translated by