how to rectify Index out of bounds error......

Hai everyone, here is the code i am trying to attempt..but it's showing Attempted to access Tm(5); index out of bounds because numel(Tm)=4.

the code is

function Fv=funsys(t,Tm)
a1 = 1.71*10^(-3);
a2 = -0.0447;
a3 = -56.46*10^(-6);
b1 = -6.57*10^(-3);
b2 = 14.84*10^(-6);
Tm(1)= 773;
Tm(4)= 493;
Fv(1,1) = a1+(a2*(Tm(1)-300))+(a3*(Tm(1)-Tm(4)));
Fv(2,1) = a1+(a2*(Tm(2)-300))+(a3*(Tm(2)-Tm(5)));
Fv(3,1) = a1+(a2*(Tm(3)-300))+(a3*(Tm(2)-Tm(6)));
Fv(4,1) = (b1*((-3*Tm(4))+(4*Tm(5))+(-1*Tm(6))))+(b2*(Tm(1)-Tm(4)));
Fv(5,1) = (b1*((-1*Tm(4))+Tm(6)))+(b2*(Tm(2)-Tm(5)));
Fv(6,1) = (b1*((1*Tm(4))+(-4*Tm(5))+(3*Tm(6))))+(b2*(Tm(3)-Tm(6)));

please help me how to rectify my problem and also give suggestions how to solve this system of ode equations....reply me soon...

[pfb]

Hi,

have you taken a look at the code in your post?

Not very readable...

Please format it using the "{}code" button in the editor.

Anyway, it seems to me that the error is what it says. You never assign Tm(5), and yet you ask matlab to access that. How is matlab supposed to know what's Tm(5)?

Same goes for Tm(6).

[Jan]

Note: While 1.71*10^(-3) is an expensive calculation, 1.71e-3 is a constant. So prefer the 2nd.

[Image Analyst]

How did you call this function? What did you send in for t and Tm? And have you seen this, which will definitely solve your problem.

Answer 1

[the cyclist]

Just adding a little specificity to what pfb commented on:

In the line

Fv(2,1) = a1+(a2*(Tm(2)-300))+(a3*(Tm(2)-Tm(5)));

you reference the element

Tm(5)

but you have not yet defined the Tm(5) element.

Answer 2

[Star Strider]

Your initial conditions vector sets the length of ‘Tm’, so be sure it is a 6-element vector.