Time Series package w v 3.0

*To*: mathgroup at smc.vnet.net*Subject*: [mg15166] Time Series package w v 3.0*From*: "Atul Sharma" <mdsa at musica.mcgill.ca>*Date*: Thu, 17 Dec 1998 00:27:45 -0500*Organization*: McGill University Computing Centre*Sender*: owner-wri-mathgroup at wolfram.com

I have been using the Time Series Analysis package with Mathematica 3.01 for some time. Usually, I am analyzing the spectrum of experimental data, but today needed to analyze the spectrum of an AR model object generated by the BurgEstimate routine. I discovered that when I try to use the Spectrum command on a model object, I get an error that has to do with the ComplexToTrig function: The output (using the example in the text) is In: spc=Spectrum[ARModel[{1,-0.5},1],w] Out[122]= 1/(2 Pi ) (( TimeSeries`TimeSeries`Private`ComplexToTrig[ 1\/\(\(2.25`\[InvisibleSpace]\) - 1.5`\ E\^\(\(-I\)\ w\) - 1.5`\ E\^\(I\ w\) + 0.5`\ E\^\(\(-2\)\ I\ w\) + 0.5`\ E\^\(2\ I\ w\)\)])\)\)\) I recall that when I bought the package, I had to comment out the Needs[] for a Algebra`Trigonometry`, which loaded the ComplexToTrig function. I assumed this was a holdover from v 2.0 which had become a kernel function (ExpToTrig). The package worked fine until I tried to analyze a model object, as noted above. In the definition of the Spectrum[ ], I replaced the call to ComplexToTrig with ExpToTrig without any luck, and also modified Expand to TrigExpand, but these changes kill the function. Any ideas would be greatly appreciated. A. Sharma