[datatable-help] Sistematically construction of 2 variables in data table

[Frank S.]

Hi Michael, The dsum variable results from datep, contained in the original data table I give, called dt. Thus, dsum is just to keep those dates contained in datep variable which correspond to 31st december or to thelast register within each id. Please, tell me for any further questions. I'm aware that the question is not easy. Regards 		 	   		  
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