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3
votes
1answer
80 views

What is a proper way to represent multidimensional data in TemporalData?

A TemporalData object can host multiple paths or it can admit a ValueDimensions option value greater than unity. In the former ...
2
votes
4answers
214 views

How to superimpose a curve fit on top of a TimeSeries plot?

This is a remarkably simple question for which I was not able to find an answer in the documentation. For concreteness, suppose that we have some time series data, such as this (example taken ...
2
votes
0answers
174 views

How to extract the conditional variance from a fitted GARCH model?

In R's garchFit (fGarch) I can simply call "@h.t" or "@sigma.t" to get the conditional variance or standard deviation for a fitted GARCH model. Is there a convenient way achieve this with Mathematica'...
2
votes
1answer
96 views

How can I use WienerProcess with TimeSeriesForecast?

I created a TimeSeries from Date-Value-Pairs, which I imported from a .csv-File diffp = Import["path/difficultyp.csv", "Data"]; tsdiff = TimeSeries[diffp]; I ...
2
votes
1answer
84 views

EstimatedProcess estimate biased?

I'm estimating the ARProcess parameters of a set of 1000 time series generated with an ARProcess and RandomFunction. Each time ...
0
votes
1answer
311 views

Exponential fit for time series

I'm pretty new to time series, but I'm now practising with it in order to obtain an exponential envelope of my experimental data. I start by importing data, I create the time series, I calculate the ...
2
votes
1answer
80 views

How to get standard errors of fitted noise variance and constant for random process, e.g., ARProcess from TimeSeriesModelFit

I want to know how to get the standard errors (and hopefully the CovarianceMatrix) for the constant and noise variance parameters of (say) an ...
3
votes
0answers
110 views

Estimating VARX(p,q) models in Mathematica

I would like to estimate the parameters of a vector autogressive process VARX(p,q) with n endogenous variables y and m exogenous variables x: $$ y_t = v + B_1 y_{t-1} + ... + B_p y_{t-p} + \theta_0 ...
0
votes
2answers
139 views

Can NonlinearModelFit be used instead of TimeSeriesModelFit without loss of generality?

I am trying to model sales seasonality. As I am unfamiliar with TimeSeriesModelFit[], I am using NonlinearModelFit[]. However, ...
4
votes
1answer
212 views

Why is TimeSeriesForecast linear?

When I use FinancialData with TimeSeriesForecast, the resulting graph is always linear and thus not very accurate. ...
1
vote
1answer
195 views

Traffic growth forecast: showing the change of linear regression

The following picture shows a changement in the trend of data. (The data used are available here). Is there any tool that can show this change of trend? Until now I managed to show even more ...
4
votes
1answer
550 views

TimeSeriesModelFit incorrect?

I am trying to determine the optimal model for time series data (1592 observations). When I run TimeSeriesModelFit, Mathematica selects $AR(1)$ model, the estimated ...