ArrayIndexOutOfBoundsException SparseMatrix

[PEDRO MANUEL JIMENEZ RODRIGUEZ]

Hi all,

I'm trying to set all values of a SparseMatrix structure using multiple threads 
but I'm getting an error of "ArrayIndexOutBoundsException" even when access 
indexes are correct. In fact, when I subtitude SparseMatrix structure for a 
double array I didn't get any error.

Does any one have any idea what could be the problem?

Error:
     matrixK.set(
                        index,
                        j,
                        Math.exp((-1 * (matrixD.get(index, j) * matrixD.get(
                                index, j))) / epsilon));


No error:
        matrixK[index][j] = Math.exp((-1 * (matrixD.get(index, j) * matrixD.get(
                        index, j))) / epsilon);

Thanks a lot.

Pedro.