### 3.1.78 NoteColumn

NoteColumn objects are created by: Rhythmic_column_engraver.

Standard settings:

> `axes` (list):

>   `'(0 1)`

>   List of axis numbers. In the case of alignment grobs, this should contain only one number.

> `horizontal-skylines` (pair of skylines):

>   `ly:separation-item::calc-skylines`

>   Two skylines, one to the left and one to the right of this grob.

> `skyline-vertical-padding` (number):

>   `0.15`

>   The amount by which the left and right skylines of a column are padded vertically, beyond the `Y-extent`s and `extra-spacing-height`s of the constituent grobs in the column. Increase this to prevent interleaving of grobs from adjacent columns.

> `X-extent` (pair of numbers):

>   `ly:axis-group-interface::width`

>   Extent (size) in the X direction, measured in staff-space units, relative to object’s reference point.

> `Y-extent` (pair of numbers):

>   `#<unpure-pure-container #<primitive-procedure ly:axis-group-interface::height> #<primitive-procedure ly:axis-group-interface::pure-height> >`

>   Extent (size) in the Y direction, measured in staff-space units, relative to object’s reference point.

This object supports the following interface(s): axis-group-interface, grob-interface, item-interface, note-column-interface and separation-item-interface.

#### Internals Reference v2.18.2 (稳定分支).