ReQL command: avg

Command syntax

sequence.avg([field | function]) → number
r.avg(sequence, [field | function]) → number

Description

Averages all the elements of a sequence. If called with a field name, averages all the values of that field in the sequence, skipping elements of the sequence that lack that field. If called with a function, calls that function on every element of the sequence and averages the results, skipping elements of the sequence where that function returns null or a non-existence error.

Produces a non-existence error when called on an empty sequence. You can handle this case with default.

Example: What’s the average of 3, 5, and 7?

r.expr([3, 5, 7]).avg().run(conn, callback)

Example: What’s the average number of points scored in a game?

r.table('games').avg('points').run(conn, callback)

Example: What’s the average number of points scored in a game, counting bonus points?

r.table('games').avg(function(game) {
    return game('points').add(game('bonus_points'))
}).run(conn, callback)

Example: What’s the average number of points scored in a game? (But return null instead of raising an error if there are no games where points have been scored.)

r.table('games').avg('points').default(null).run(conn, callback)