7.10.1.10. statsmodels.stats.diagnostic.het_arch¶
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statsmodels.stats.diagnostic.
het_arch
(resid, maxlag=None, autolag=None, store=False, regresults=False, ddof=0)[source]¶ Engle’s Test for Autoregressive Conditional Heteroscedasticity (ARCH)
Parameters: resid : ndarray, (nobs,)
residuals from an estimation, or time series
maxlag : int
highest lag to use
autolag : None or string
If None, then a fixed number of lags given by maxlag is used.
store : bool
If true then the intermediate results are also returned
ddof : int
Not Implemented Yet If the residuals are from a regression, or ARMA estimation, then there are recommendations to correct the degrees of freedom by the number of parameters that have been estimated, for example ddof=p+a for an ARMA(p,q) (need reference, based on discussion on R finance mailinglist)
Returns: lm : float
Lagrange multiplier test statistic
lmpval : float
p-value for Lagrange multiplier test
fval : float
fstatistic for F test, alternative version of the same test based on F test for the parameter restriction
fpval : float
pvalue for F test
resstore : instance (optional)
a class instance that holds intermediate results. Only returned if store=True
Notes
verified agains R:FinTS::ArchTest