ur.df-class {urca}R Documentation

Representation of class 'ur.df'

Description

This class contains the relevant information by applying the augmented Dickey-Fuller unit root test to a time series.

Slots

y:
Object of class "vector": The time series to be tested.
model:
Object of class "character": The type of the deterministic part, either "none", "drift" or "trend". The latter includes a constant term, too.
lags:
Object of class "integer": Number of lags for error correction.
cval:
Object of class "matrix": Critical values at the 1%, 5% and 10% level of significance.
teststat:
Object of class "numeric": Value of the test statistic.
testreg:
Object of class "ANY": The summary output of the test regression.
res:
Object of class "vector": The residuals of the test regression.
test.name:
Object of class "character": The name of the test, i.e `Augmented-Dickey-Fuller Test'.

Extends

Class `urca', directly.

Methods

Type showMethods(classes="ur.df") at the R prompt for a complete list of methods which are available for this class.

Useful methods include

show:
test statistic.
summary:
like show, but critical value and summary of test regression added.
plot:
Diagram of fit plot, residual plot and their acfs' and pacfs'.

Author(s)

Bernhard Pfaff

References

Dickey, D. A. and Fuller, W. A. (1979), Distributions of the Estimators For Autoregressive Time Series with a Unit Root, Journal of the American Statistical Association, 75, 427–431.

Hamilton (1994), Time Series Analysis, Princeton University Press.

See Also

ur.df and urca-class


[Package urca version 0.7-9 Index]