statsmodels.stats.diagnostic.het_arch¶
-
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
residuals from an estimation, or time series
- maxlag
int
highest lag to use
- autolag
None
orstr
If None, then a fixed number of lags given by maxlag is used.
- storebool
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+q for an ARMA(p,q) (need reference, based on discussion on R finance mailinglist)
- resid
- 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
- lm
Notes
verified against R:FinTS::ArchTest