arch.univariate.APARCH.backcast¶ APARCH.backcast(resids: ndarray[Any, dtype[float64]]) → float | ndarray[Any, dtype[float64]]¶ Construct values for backcasting to start the recursion Parameters:¶ resids: ndarray[Any, dtype[float64]]¶Vector of (approximate) residuals Returns:¶ backcast – Value to use in backcasting in the volatility recursion Return type:¶ float