Grid¶

Grid value class for gridline configuration.

Ferrum — a statistical visualization library with a Rust core.

Grid `dataclass` ¶

Theme-level grid configuration controlling major and minor gridlines.

Accepted by Theme(grid=...) / Theme.update(grid=fr.Grid(...)). Passing a bare bool remains valid (maps to the major enable flag).

Shorthand resolution. The bare color, width, dash, and opacity parameters are a fallback that sets both levels. An explicit major_* or minor_* value for that property overrides the bare value for that level only. Examples::

Grid(color="#f5f5f5")
# → major_grid_color="#f5f5f5", minor_grid_color="#f5f5f5"

Grid(color="#eee", minor_color="#f8f8f8")
# → major_grid_color="#eee", minor_grid_color="#f8f8f8"

The bare shorthand keys (color, width, dash, opacity) are never emitted to the Rust renderer; only resolved per-level keys appear in to_spec_dict() output.

Minor gridlines. minor=True renders minor gridlines on continuous axes (linear, log, time, pow, sqrt, symlog). On categorical or discretising axes (band, ordinal, quantile, threshold, bin-ordinal) there is no continuum to subdivide, so minor=True there is a semantic absence — no extra lines are drawn and no error is raised.

Parameters:

Name	Type	Description	Default
`major`	`bool`	Enable major gridlines.	`True`
`minor`	`bool`	Enable minor gridlines (continuous scales only).	`False`
`color`	`str`	Fallback color for both major and minor gridlines.	`None`
`width`	`float`	Fallback stroke width for both levels.	`None`
`dash`	`list of float`	Fallback dash pattern (SVG stroke-dasharray lengths) for both levels.	`None`
`opacity`	`float`	Fallback stroke opacity for both levels.	`None`
`major_color`	`str`	Major gridline color; overrides bare `color` for the major level.	`None`
`minor_color`	`str`	Minor gridline color; overrides bare `color` for the minor level.	`None`
`major_width`	`float`	Major gridline stroke width; overrides bare `width` for major.	`None`
`minor_width`	`float`	Minor gridline stroke width; overrides bare `width` for minor.	`None`
`major_dash`	`list of float`	Major gridline dash pattern; overrides bare `dash` for major.	`None`
`minor_dash`	`list of float`	Minor gridline dash pattern; overrides bare `dash` for minor.	`None`
`major_opacity`	`float`	Major gridline opacity; overrides bare `opacity` for major.	`None`
`minor_opacity`	`float`	Minor gridline opacity; overrides bare `opacity` for minor.	`None`

Examples:

>>> import ferrum as fm
>>> # Enable minor gridlines, both levels same colour
>>> g = fm.Grid(minor=True, color="#f5f5f5")
>>> g.to_spec_dict()
{'grid': True, 'minor': True, 'major_grid_color': '#f5f5f5', 'minor_grid_color': '#f5f5f5'}

>>> # Different colours per level
>>> g2 = fm.Grid(minor=True, color="#eeeeee", minor_color="#f8f8f8")
>>> g2.to_spec_dict()
{'grid': True, 'minor': True, 'major_grid_color': '#eeeeee', 'minor_grid_color': '#f8f8f8'}

>>> # Attach to a theme
>>> chart.theme(fm.themes.minimal.update(grid=fm.Grid(minor=True)))

to_spec_dict ¶

to_spec_dict() -> dict

Serialize to the dict shape the Rust binding expects.

Always emits grid (major enable) and minor (minor enable). Resolves shorthand → per-level: for each of color/width/dash/opacity, major level = major_X if not None else bare X; minor level = minor_X if not None else bare X. Only non-None resolved per-level styling keys are emitted. The bare shorthand keys are never present in the output.

Grid¶

Grid dataclass ¶

to_spec_dict ¶

Grid `dataclass` ¶