function to parse a factor file line.  Used by fac2real()

    Parameters
    ----------
    line : (str)
        a factor line from a factor file

    Returns
    -------
    inode : int
        the inode of the grid node
    itrans : int
        flag for transformation of the grid node
    fac_data : dict
        a dictionary of point number, factor

def parse_factor_line(line):
    """ function to parse a factor file line.  Used by fac2real()

    Parameters
    ----------
    line : (str)
        a factor line from a factor file

    Returns
    -------
    inode : int
        the inode of the grid node
    itrans : int
        flag for transformation of the grid node
    fac_data : dict
        a dictionary of point number, factor

    """

    raw = line.strip().split()
    inode,itrans,nfac = [int(i) for i in raw[:3]]
    fac_data = {int(raw[ifac])-1:float(raw[ifac+1]) for ifac in range(4,4+nfac*2,2)}
    # fac_data = {}
    # for ifac in range(4,4+nfac*2,2):
    #     pnum = int(raw[ifac]) - 1 #zero based to sync with pandas
    #     fac = float(raw[ifac+1])
    #     fac_data[pnum] = fac
    return inode,itrans,fac_data