'create and add a table for the parameter estimates
Parameters
res : results instance
some required information is directly taken from the result
instance
yname : string or None
optional name for the endogenous variable, default is "y"
xname : list of strings or None
optional names for the exogenous variables, default is "var_xx"
alpha : float
significance level for the confidence intervals
use_t : bool
indicator whether the p-values are based on the Student-t
distribution (if True) or on the normal distribution (if False)
Returns
None : table is attached'

def add_table_params(self, res, yname=None, xname=None, alpha=0.05, use_t=True):

    if (res.params.ndim == 1):
        table = summary_params(res, yname=yname, xname=xname, alpha=alpha, use_t=use_t)
    elif (res.params.ndim == 2):
        (_, table) = summary_params_2dflat(res, endog_names=yname, exog_names=xname, alpha=alpha, use_t=use_t)
    else:
        raise ValueError('params    has    to    be    1d    or    2d')
    self.tables.append(table)
