dfr std for expression

Creates a std expression for an aggregation

Signature

> dfr std

Examples

Std aggregation for a group-by

> [[a b]; [one 2] [one 2] [two 1] [two 1]]
    | dfr into-df
    | dfr group-by a
    | dfr agg (dfr col b | dfr std)
╭───┬─────┬────────╮
│ # │  a  │   b    │
├───┼─────┼────────┤
│ 0 │ one │ 0.0000 │
│ 1 │ two │ 0.0000 │
╰───┴─────┴────────╯

dfr std for lazyframe

Aggregates columns to their std value

Signature

> dfr std

Examples

Std value from columns in a dataframe

> [[a b]; [6 2] [4 2] [2 2]] | dfr into-df | dfr std
╭───┬────────┬────────╮
│ # │   a    │   b    │
├───┼────────┼────────┤
│ 0 │ 2.0000 │ 0.0000 │
╰───┴────────┴────────╯