polars mean for dataframe
Creates a mean expression for an aggregation or aggregates columns to their mean value.
This command requires a plugin
The polars mean command resides in the polars plugin. To use this command, you must install and register nu_plugin_polars. See the Plugins chapter in the book for more information.
Signature
> polars mean {flags}
Input/output types:
| input | output |
|---|---|
| polars_expression | polars_expression |
| polars_dataframe | polars_dataframe |
| polars_lazyframe | polars_lazyframe |
Examples
Mean value from columns in a dataframe
> [[a b]; [6 2] [4 2] [2 2]] | polars into-df | polars mean
╭───┬──────┬──────╮
│ # │ a │ b │
├───┼──────┼──────┤
│ 0 │ 4.00 │ 2.00 │
╰───┴──────┴──────╯Mean aggregation for a group-by
> [[a b]; [one 2] [one 4] [two 1]]
| polars into-df
| polars group-by a
| polars agg (polars col b | polars mean)
| polars collect
| polars sort-by a
╭───┬─────┬──────╮
│ # │ a │ b │
├───┼─────┼──────┤
│ 0 │ one │ 3.00 │
│ 1 │ two │ 1.00 │
╰───┴─────┴──────╯