Method: Polars::Functions#mean

Defined in:
lib/polars/functions/lazy.rb

#mean(*columns) ⇒ Expr

Get the mean value.

This function is syntactic sugar for col(columns).mean.

Examples:

df = Polars::DataFrame.new(
  {
    "a" => [1, 8, 3],
    "b" => [4, 5, 2],
    "c" => ["foo", "bar", "foo"]
  }
)
df.select(Polars.mean("a"))
# =>
# shape: (1, 1)
# ┌─────┐
# │ a   │
# │ --- │
# │ f64 │
# ╞═════╡
# │ 4.0 │
# └─────┘

df.select(Polars.mean("a", "b"))
# =>
# shape: (1, 2)
# ┌─────┬──────────┐
# │ a   ┆ b        │
# │ --- ┆ ---      │
# │ f64 ┆ f64      │
# ╞═════╪══════════╡
# │ 4.0 ┆ 3.666667 │
# └─────┴──────────┘

Parameters:

  • One or more column names.

Returns:



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# File 'lib/polars/functions/lazy.rb', line 299

def mean(*columns)
  col(*columns).mean
end