What is wrong with this line of script?

I've written: [t,h] = ode45('cylinder_tank_drain', [0, 200], h0)

it keeps coming up with an error message what just says there is an error in this line. what is wrong? :(

Answer 1

[Youssef Khmou]

Change r0 to :

 r0=linspace(0.01,0.1,length(r));

[Alice]

Thanks :)

Answer 2

[Walter Roberson]

There is no obvious error in that line. Perhaps there is an error in the previous line that is affecting it. Please post more of your script.

Also, I suggest converting to function handle form:

[t, h] = ode45(@cylinder_tank_drain, [0, 200], h0);

Answer 3

[Youssef Khmou]

The problem resides in the function "cylinder_tank_drain", if it is possible you post the function to study its input and outputs.

Answer 4

[Alice]

function [ dhdt ] = cylinder_tank_drain( t, h)
%draining of a uniform cross sectional area tank (cylinder)

r = [1:0.5:6];
A = pi.*r.^2;
r0 = [0.01:0.01:0.1];
a0 = pi.*r0.^2;
g = 9.8;

dhdt = (-a0.*sqrt(2*g.*h))./A;

[Walter Roberson]

Your "r" is length 11. Your "r0" is length 10. You are trying to combine two vectors of different lengths.

[Alice]

Thanks!!