[Rd] R-intro: length of 'ifelse' result

Suharto Anggono Suharto Anggono suharto_anggono at yahoo.com
Wed Sep 14 17:15:35 CEST 2016

In "An Introduction to R" Version 3.3.1, in "9.2.1 Conditional execution: if statements", the last paragraph is the following:
There is a vectorized version of the if/else construct, the ifelse function. This has the form ifelse(condition, a, b) and returns a vector of the length of its longest argument, with elements a[i] if condition[i] is true, otherwise b[i].

In fact, ifelse(condition, a, b) returns a vector of the length of 'condition', even if 'a' or 'b' is longer.

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