Which filter do I have to use?

I have rainfalls data (11/5/1981 ~ 11/5/2021) for 41 years.

If I want to see anual rainfall data (January ~ December) for 41years, then which filter do I have to use??

Answer 1

[Star Strider]

See if the groupsummary function produces the desired reault.

It will be necessary to experiment with it.

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