def _corr_dist(mat_corr):
    """ Compute a distance matrix based on correlation.

    Parameters
    ----------
    mat_corr: np.ndarray[ndim=2, dtype=float] or pd.DataFrame
        Matrix correlation.

    Returns
    -------
    mat_dist_corr: np.ndarray[ndim=2, dtype=float] or pd.DataFrame
        Matrix distance correlation.

    """
    return ((1 - mat_corr) / 2.) ** 0.5