New user - looking at a season's data

[petebarnden]

Hello, 

I'm fairly new to the camtrapR package but I have a large (22000) image dataset and I would like to see if I can use this to look at activity levels across the season in addition to the daily cycles. Is there a way to adapt one of the functions (activityDensity for example) to do this over a few months rather than a day.

Thanks for any help you can give

Pete 

[Juergen Niedballa]

Hi Pete,

there's no built-in function to achieve this. There's also differences in the underlying statistics between daily and seasonal statistics. The activity plot functions from package overlap use circular statistics to ensure that the two ends of the daily distribution meet. I'm not sure that makes sense in seasonal data (it may under certains conditions, e.g. over a complete year, but it may be more far-fetched than over a 1-day cycle). A few months would probably not meet these assumptions.

Nevertheless, if you have a record table with all the species of interest and the record's date/time, it should be rather straightforward to code and plot manually though, without the fancy circular stats. You could for instance plot weekly / monthly histograms of the number of detections. The package lubridate helps a lot in extracting these and more from date/time objects. 

But be aware that all these methods ignore imperfect detection and  results may be biased. 

Best regards,

Jürgen

[petebarnden]

Thanks  Jürgen, 

I was wondering if that would be the case, but thanks for the advice, I will look at lubridate.

Pete