CODEWITHSUNDEEP
rboolean
Mr Guliarte
Mr Guliarte

Reputation: 739

What does * means in R?

For instance:

> TRUE * 0.5
   0.5
> FALSE * 0.5
   0

I don't know if the secret here is the * character itself or the way R encodes logical statements, but I can't understand why the results.

Upvotes: 0

Views: 780

Answers (1)

IRTFM
IRTFM

Reputation: 263411

R has a fairly loose type system and rather freely does coercion, hopefully when it is sensible. When coerced to numeric by *, logical values become 0 (FALSE) and 1 (TRUE), your expression gets evaluated with the usual mathematical convention of all values times 0 equal 0, and all values times 1 equal the value. The one exception to that rule in the numeric domain is Inf * 0 returns NaN. Character values have no "destination"-type when composed with "*", so "1"*TRUE throws an error.

Upvotes: 3

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