python - 如何在 statsmodels 中创建约束回归？

Question

我需要在下面的线性回归中添加一个约束，以便y_pred [i] >= y_pred [i+1]

from patsy import dmatrix
import statsmodels.api as sm

xknot = dmatrix("bs(x, knots=(0.0001,1,2,4,6,8,9.3), degree=3, include_intercept=False)", 
                        {"x": x},return_type='dataframe') 

fit = sm.GLM(y, xknot).fit() 

y_pred = fit1.predict(dmatrix("bs(x, knots=(0.0001,1,2,4,6,8,9.3), include_intercept=False)",
                             {"x": x}, return_type='dataframe')) ```