Numerical Integration ( Double integral with log singularity)

>>>>> "ccitak" == ccitak  <ccitak at metu.edu.tr> writes:

    ccitak> Hi, my name is Can studying at Aerospace Engineering Department of Middle East Technical University
    ccitak> I couldnt find the option for,
    ccitak> ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? Integral from 0 to L ( Integral from 0 to L (
    ccitak> ln(abs(x1-x2))))dx1dx2
    ccitak> How can double integral shown above be calculated numerically ?

Not as it's written since you probably want to say log instead of ln
and you didn't give a value for L.

However, in this case, maxima can do the integral symbolically:

assume(L>0);
integrate(integrate(log(abs(x1-x2)), x1, 0, L), x2, 0, L);

(2*L^2*log(L)-3*L^2)/2

Don't know if the answer is correct or not, but it looks reasonable.

Ray