utils.py 文件源码

def from_sym_2_tri(symm):
    """convert a 2D symmetric matrix to an upper
       triangular matrix in 1D format

    Parameters
    ----------

    symm : 2D array
          Symmetric matrix


    Returns
    -------

    tri: 1D array
          Contains elements of upper triangular matrix
    """

    inds = np.triu_indices_from(symm)
    tri = symm[inds]
    return tri