Method: Polars::Functions#max

Defined in:
lib/polars/functions/aggregation/vertical.rb

#max(*names) ⇒ Expr

Get the maximum value.

Syntactic sugar for col(names).max.

Examples:

Get the maximum value of a column.

df = Polars::DataFrame.new(
  {
    "a" => [1, 8, 3],
    "b" => [4, 5, 2],
    "c" => ["foo", "bar", "foo"]
  }
)
df.select(Polars.max("a"))
# =>
# shape: (1, 1)
# ┌─────┐
# │ a   │
# │ --- │
# │ i64 │
# ╞═════╡
# │ 8   │
# └─────┘

Get the maximum value of multiple columns.

df.select(Polars.max("^a|b$"))
# =>
# shape: (1, 2)
# ┌─────┬─────┐
# │ a   ┆ b   │
# │ --- ┆ --- │
# │ i64 ┆ i64 │
# ╞═════╪═════╡
# │ 8   ┆ 5   │
# └─────┴─────┘
df.select(Polars.max("a", "b"))
# =>
# shape: (1, 2)
# ┌─────┬─────┐
# │ a   ┆ b   │
# │ --- ┆ --- │
# │ i64 ┆ i64 │
# ╞═════╪═════╡
# │ 8   ┆ 5   │
# └─────┴─────┘

Parameters:

  • names (Array) —

    Name(s) of the columns to use in the aggregation.

Returns:

[View source]

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# File 'lib/polars/functions/aggregation/vertical.rb', line 135

def max(*names)
  col(*names).max
end