How to find out seasonality at weekly data?

[Maria Panina]

Hello)
I’m an EViews7-user

Could you please tell me how can I check my weekly data for seasonality?
Is there are any other way to do it then adding @seas(1) @seas(2) ........ @seas(52) to the model?
please, help me asap

[trubador]

The shortcut to what you are trying to do is:

Code: Select all

@expand(@datepart(@date, "WW"))

Other than that, you might also want to check "diurnal pattern", which is analogous to seasonality in high frequency data. Moreover, I suggest you to adjust your series prior to including them in your model. Otherwise, you may quickly run out of degrees-of-freedom.

An effective (but not necessarily efficient) way to seasonally adjust your series is to use "time series decomposition" analysis, where you can define the seasonality as a state variable.