C++ :: Function Outputs Different Matrix

It is getting more and more annoying, everytime i progress the next hurdle is just bigger. The problem is i want to calculate inverse of a matrix but using .inv gives a matrix full of -1.#QNAN values so i decided to write one my self

a function which returns the inverse matrix but something strange happens.

when i debug through the function code it works well and check the matrix that will be returned and the elements are correct.

when the function is called and output matrix is resulted. the element of the matrix is different.

matrix = inversemat(matrx)
inside function, invmat= 3 1 2, 3 5 1, 8 1 2
outside the function matrix = -9.1249e+61 wtf.

here is the code

int main() {
double matrx[3][3]={{1,2,3},{0,1,4},{5,6,0}};
Mat matrx1(3,3,CV_64F,matrx);
Mat inmat;
inmat=inversemat(matrx1);

[Code] ...

invmat elements are correct, as for inmat the elements are too small -9.212412e+61

What is going on, when the matrix is returned.