search for: id_remap

Is the phrase "index <- match(x, sort(unique(x)))" reliable, in the sense that it will never return NA? Context: Calculation of survival curves involves the concept of unique death times. I've had reported cases in the past where survfit failed, and it was due to the fact that two "differ by machine precision" values would sometimes match and sometimes not,

...o is to use rank(): r <- rank(x, ties.method="min") # could use "max" Think of 'r' as a unique ID assigned to each value in 'x'. This ID takes its values in the (1,length(x)) range but we want it to take its values in the (1,length(unique(x))) range: ID_remapping <- cumsum(tabulate(r, nbins=length(r)) != 0L) index <- ID_remapping[r] 'index' will be the same as 'match(x, sort(unique(x))' but doesn't rely on the assumption that match() and unique() agree on equality between 2 floating point values. Unfortunately rank() is ve...