Function det

src/api/c/det.cpp:32–70

template<typename T>
T det(const af_array a) {
    using namespace detail;
    const Array<T> A = getArray<T>(a);

    const int num = A.dims()[0];

    if (num == 0) {
        T res = scalar<T>(1.0);
        return res;
    }

    std::vector<T> hD(num);
    std::vector<int> hP(num);

    Array<T> D       = createEmptyArray<T>(dim4());
    Array<int> pivot = createEmptyArray<int>(dim4());

    // Free memory as soon as possible
    {
        Array<T> A_copy = copyArray<T>(A);

        Array<int> pivot = lu_inplace(A_copy, false);
        copyData(&hP[0], pivot);

        Array<T> D = diagExtract(A_copy, 0);
        copyData(&hD[0], D);
    }

    bool is_neg = false;
    T res       = scalar<T>(is_neg ? -1 : 1);
    for (int i = 0; i < num; i++) {
        res = res * hD[i];
        is_neg ^= (hP[i] != (i + 1));
    }

    if (is_neg) { res = res * scalar<T>(-1); }

    return res;
}

af_err af_det(double *real_val, double *imag_val, const af_array in) {
    try {