I am trying to do a side project to get a better understanding of the whole data science after completing my online course. Am now in an early stage of just laying out the project in general and was wondering if you can put time series data and just variable (normalized if necessary) in a multivariable polynomial regression model?
Can you practically use Polynomial Regression on time series data? YES YOU CAN!
But that does not mean you should!
Time series data and non time series data are 2 very different kind. The models which can work on time and non time series data are also different. Even the preprocessing techniques used in non time series data cannot be simple used in time series data.
The reason for this is that there is an inherent order/sequence present in time series datasets whereas non time series datasets do not have that sequence.
Polynomial Regression is usually used in non time series data. You can try training it on your time series dataset to see what kind of results you get. These kinds of models do not take into account the sequence/order into account so I would not hope for much.
Instead you could use ARIMA, SARIMA, SARIMAX, VAR, VARMA, VARMAX, HWES or more complex Deep Learning models like RNN's, LSTM's and more. They would be much more appropriate results.