Partial derivative

[Huaihai Guo]

First of all, I have a complicated multi-variable integral. like:

f(x,y,z) = integral(x..., y..., z...)

This integral cannot be integral out to a simple expression. I can get a certain result through numerical integral quad(x, Xmin, Xmax) for giving certain values to y and z.

Now, I want to have get the partial derivative of f with respective to y or z. I tried diff(), and gradient(). Both of them can not give me a none integral function.

Is there another way to resolve this problem??

Thanks

[Vincent Morio]

"Huaihai Guo" <hg...@njit.edu> wrote in message <gc6brm$1vc$1...@fred.mathworks.com>...

Formal computations are performed under Matlab Symbolic toolbox by using a Maple kernel. Try to use directly Maple to perform your analytical computations.

Cheers,

V. Morio
PhD student in Automatic Control
IMS lab./University of Bordeaux, France

[Huaihai Guo]

> Formal computations are performed under Matlab Symbolic toolbox by using a Maple kernel. Try to use directly Maple to perform your analytical computations.
>

But, quad() is not a symbolic function. In Symbolic toolbox, the integral function is int(), which can not give me a result for my complicated multi-variables expression.

Anyway, thank you for your help.

[Bruno Luong]

"Huaihai Guo" <hg...@njit.edu> wrote in message <gcdd35$eva$1...@fred.mathworks.com>...

>
> But, quad() is not a symbolic function. In Symbolic toolbox, the integral function is int(), which can not give me a result for my complicated multi-variables expression.
>

Hint: Usually you can permute the integral and derivative (careful, this is always not true with function having strong singularity).

Bruno