A practical case of SPSS establishing a time series additive seasonal model

experiment

name

Sparse coefficient model and seasonal model

experiment

content

1. Simple season model

experiment

purpose

1. Master the sparse coefficient model

2. Skilled in building seasonal models

 

table of Contents

Simple seasonal model structure

Model building

Timing diagram

Difference smoothing

White noise test

Model ordering

Parameter estimation and model checking

Model prediction


Recommended reading

  1. Use Python to complete the basics of time series analysis
  2. A practical case of SPSS establishing a time series multiplication season model
  3. Practical case of building a time series ARIMA model in Python

Simple seasonal model structure

Model building

Timing diagram

The time series diagram shows that the series contains both long-term trends and seasonal effects with annual cycles

 

Difference smoothing

Do 1st-order difference to eliminate the trend of the original sequence, and then do 4-step difference to eliminate the influence of seasonal effects. The sequence diagram of the sequence after the difference is:

Unit root test:  

White noise test

The test results show that the differential sequence is a stationary non-white noise sequence, and the differential sequence needs to be further fitted to the ARMA model.

Model ordering

      The autocorrelation graph shows a clear downward trajectory, which is a typical trailing attribute. The partial autocorrelation plot except for the 1st and 4th order partial autocorrelation coefficients is significantly larger than 2 times the standard deviation. So try to fit ARIMA(4,1,0)*(0,1,0)4

Parameter estimation and model checking

 

x2, x3, P>α, fail the significance test

Significance test of the model:

The test results show that the residual sequence is a white noise sequence, and the parameter significance test shows that both parameters are significantly non-zero.

Model prediction

 

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Origin blog.csdn.net/qq_45176548/article/details/112006848