definite numerical integration

[roberto]

hello,
i need some hint about the following topic:

1. take a function f(r; a), where "a" is a parameter, whose analytical
form i don't know explictly but i can evaluate it point by point in a
given interval [0,r_max]
(i already wrote Octave code for this);

2. i have to evaluate the definite integral of f(r; a) in [0,r*]
(where r*<r_max);

3. doing this, evaluating the integral by varying r* in [0,R] (e.g. R = 110)
i'll have a function F(r*,a) where a should be obtained by imposing
some boundary condition;

i looked for some help into Octave like 
http://octave.sourceforge.net/index/Q.html

but in libraries like:
[v, ier, nfun, err] = quad (f, a, b, tol, sing) 

the function to be integrated are to be inserted by their explicit formulation
which i don't have now, as already stated above;

thank you very much for any help about this topic, since it's the last
step of my work up to now
bye
-- 
roberto



-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
-------------------------------------------------------------