*
* Example 4.1.5 from pp 119-122
*
* This uses the ARMASpectrum procedure, which takes an input ARMA model and
* produces a graph of its spectral density.
*
equation(noconst,coeffs=||.7||) ar1 y 1 0
@ARMASpectrum(footer="Figure 4-3") ar1
equation(noconst,coeffs=||-.7||) ar1 y 1 0
@ARMASpectrum(footer="Figure 4-4") ar1
equation(noconst,coeffs=||.9||) ma1 y 0 1
@ARMASpectrum(footer="Figure 4-5") ma1
equation(noconst,coeffs=||-.9||) ma1 y 0 1
@ARMASpectrum(footer="Figure 4-6") ma1