Quad command

Question

Cyberz 2012-5-16

Is there a way to use the numeric quadrature functions (quad commands) with functions that change? Say I define some symbolic functions on x

for i=1:n
f(i)=sen(2*i*pi*x - 1)
end

And then I'd like to create matrix components, which are the integrals of those functions or a combinations of them, say:

for i=1:n
for j=1:n
A(i,j) = quad('f(i)*f(j)+2*i-3*j',0,L)
end
end

Is there a way to do this? With the '' in quad it just doesn't work. Thanks in advance.

Answer 1

Cyberz 2012-5-16

Found a way... say:

syms x
for i=1:n
    f(i)=i*2*x-sin(2*i*x)
end

Then we may have a product of several functions...

d = f(p)*f(n)*f(i)*...

We can just use quadv with char command to solve it:

quadv(char(d),LowerLimit,UpperLimit)

:D