statsmodels.robust.norms.TrimmedMean.rho¶ TrimmedMean.rho(z)[source]¶ The robust criterion function for least trimmed mean. Parameters:¶ zarray_like1d array Returns:¶ rhondarrayrho(z) = (1/2.)*z**2 for |z| <= c rho(z) = (1/2.)*c**2 for |z| > c