public class ARMAEx3 extends Object
Fits an \(\text{ARMA}(2,1)\) to the Wolfer sunspot data and produces a forecast table.
Consider the Wolfer Sunspot Data (Anderson 1971, p. 660) consisting of the number of sunspots observed each year from 1749 through 1924. The data set for this example consists of the number of sunspots observed from 1770 through 1869. An \(\text{ARMA}(2,1)\) model is fitted to these data using the Method of Moments. Withbackward_origin=3
, the
forecast
method is used to obtain forecasts starting from 1866,
1867, 1868, and 1869, respectively. Note that the values in the first row of
the matrix returned by this method are the one-step ahead forecasts for 1867,
1868, ..., 1870. The values in the second row are the two-step ahead
forecasts for 1868, 1869, ..., 1871, etc.
Method getForecast
is used to compute the one-step ahead
forecasts setting backward_origin
= 10. This obtains the
one-step ahead forecasts for the last 10 observations in the series, i.e.
years 1860-1869, plus the next 5 years. The upper 90% confidence limits are
computed for these forecasts using the getDeviations
method.
Constructor and Description |
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ARMAEx3() |
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