Rickerウェーブレット変換のC実装

pythonのScipyのコードを書き換えて
テキストアドレスhttps://github.com/scipy/scipy/blob/v0.13.0/scipy/signal/wavelets.py#L267

double *rickerwavelet(int points, double a)
{
    const double pi = 3.14159265359;
    double A = 2 / (sqrt(3 * a) * pow(pi, 0.25));
    const double wsq = a * a;
    double tsq, mod, gauss;

    double *wricker;
    double vec;
    int i;

    wricker = (double*) calloc (points, sizeof(double));

    for (i = 0; i < points; ++i) {
        vec = i - (points - 1.0) / 2;
        tsq = vec * vec;
        mod = (1 - tsq / wsq);
        gauss = exp(-tsq / (2 * wsq));

        wricker[i] = A * mod * gauss;
    }
    return(wricker);
}