This is rather vague - it would help us if you told us what you have ( in terms of measurement and structure eg daily count of vehicle crashes at a 100 sites in 20 cities and have daily measurements of weather in each city ) and what you want to do with it.

Thanks for the reply Mr. Kelvyn Jones. My data has crash event recorded on daily basis across the districts in Tamil Nadu state. It collects variables related to driver, vehicle, crash, environment and road details. Also, has injury details of people involved in the crash. My objective is to structure the panel data and identify the contributory factors causing the crash severity. All variables in the data are categorical.

When you say 'across', do you mean each district separately, or is the row the entire state. Is the data a row for each crash; or has it been aggregated to some count? You really need the counterfactual of the non crashes; that is reflect how much traffic is on that section of the road at that time in those conditions.

Is the data in wide format - that is each row represents a day or long format? https://stackoverflow.com/questions/2185252/reshaping-data-frame-from-wide-to-long-format

It is worth putting a small extract of how you data is and how you want it.

Thank you for the information. I mean, each crash in a district is row wise not aggregated. The data is in long format not wide format. Sorry to say, I am not supposed to share data but is there any material available on how to structure crash data in panel format. It would be really helpful for me to proceed further in my research work

Blimey. So you cannot make up plausible data!

Oh!, Let me try to structure with available information from literature. If you come across any article, please do share Mr. Kelvyn Jones. Thank you for taking your time to answer this query.

Have a look at

Modelling road accidents from national datasets: a case study of Great Britain

Thesis Modelling road accidents from national datasets: a case stud...

Thanks Mr. Kelvyn Jones. I will go through it.