czeildi/cumulative_uniqueN.R

Created June 11, 2017 10:28

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compute cumulative unique N with R's data.table package

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cumulative_uniqueN.R

	dt <- data.table(x = c(4,4,2,5,4,2,3))
	dt[, g := .GRP, by = x]
	dt[, cumuniquen := cummax(g)]

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