Simple solution to a simple problem

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Chris
Chris il 14 Giu 2013
Hey, Im trying to write an algorithm to compute the integral of a user inputted function with limits. I wrote the following code:
function I=Simpson38(Fun,a,b)
N=3;
dif=1;
I1=0;
func=inline(Fun);
while dif>0.001
h=(b-a)/N;
Ia=(h*3/9)*(func(1)+func(N+1));
Ib=(h*3/9)*(2*sum(func(4:3:(N-2))));
Ic=(h*3/9)*(3*sum(func(2:3:(N-1)))+sum(fun(3:3:N-1)));
I2=Ia+Ib+Ic;
dif=(I1-I2)/I2;
I1=I2;
N=N*2;
end
I=I1;
When i run the code i get the following error: ??? Error using ==> inlineeval at 15 Error in inline expression ==> 1/(1+9*x.^2) Matrix dimensions must agree.
Error in ==> inline.subsref at 27 INLINE_OUT_ = inlineeval(INLINE_INPUTS_, INLINE_OBJ_.inputExpr, INLINE_OBJ_.expr);
Error in ==> Simpson38 at 9 Ib=(h*3/9)*(2*sum(func(4:3:(N-2)))); What could be the problem?

Risposte (1)

Richard Brown
Richard Brown il 14 Giu 2013
Try
1./(1 + 9*x.^2)
i.e. a '.' before the division
  2 Commenti
Chris
Chris il 14 Giu 2013
Worked! Thanks!
Richard Brown
Richard Brown il 16 Giu 2013
Great! Please "accept" the answer so people browsing the forum knows it's been answered

Accedi per commentare.

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