color_ramp¶

Color-ramp and classification helpers for data-driven vector symbology.

Mirrors packages/core/src/color-ramp.ts and the graduated/categorized stop-building in StylePanel.tsx so a choropleth built from Python produces the same vectorStyleStops the app would compute from the UI. The ramp names match VECTOR_COLOR_RAMPS exactly, so a ramp chosen here renders identically.

get_color_ramp ¶

get_color_ramp(name: str) -> list[str]

Return a ramp's anchor colors, falling back to the default ramp.

Parameters:

Name	Type	Description	Default
`name`	`str`	A ramp name (e.g. `"viridis"`).	required

Returns:

Type	Description
`list[str]`	A fresh list of the ramp's anchor hex colors, or the default ramp's when
`list[str]`	`name` is unknown. A copy is returned so callers cannot mutate the
`list[str]`	shared `VECTOR_COLOR_RAMPS` entries.

interpolate_hex ¶

interpolate_hex(start: str, end: str, ratio: float) -> str

Linearly interpolate between two #rrggbb colors.

Parameters:

Name	Type	Description	Default
`start`	`str`	Start hex color.	required
`end`	`str`	End hex color.	required
`ratio`	`float`	Blend factor in `[0, 1]`.	required

Returns:

Type	Description
`str`	The interpolated `#rrggbb` color.

interpolate_ramp_colors ¶

interpolate_ramp_colors(name: str, count: int) -> list[str]

Sample a ramp into count evenly spaced colors (mirror of TS helper).

Parameters:

Name	Type	Description	Default
`name`	`str`	The ramp name.	required
`count`	`int`	Number of colors to produce.	required

Returns:

Type	Description
`list[str]`	`count` hex colors (a single end color when `count <= 1`).

equal_interval_breaks ¶

equal_interval_breaks(minimum: float, maximum: float, count: int) -> list[float]

Build count evenly spaced breaks across [minimum, maximum].

quantile_breaks ¶

quantile_breaks(values: list[float], count: int) -> list[float]

Build count quantile breaks from a numeric sample (mirror of TS helper).

graduated_stops ¶

graduated_stops(values: list[Any], *, class_count: int = 5, color_ramp: str = 'viridis', classification_scheme: str = 'equal-interval') -> list[dict[str, Any]]

Build graduated vectorStyleStops from numeric values.

Mirrors createGraduatedStops in StylePanel.tsx: non-numeric values are dropped, breaks come from the chosen scheme, and colors are sampled from the ramp. The result is a list of {"value", "color"} stop dicts the app renders as an interpolate expression.

Parameters:

Name	Type	Description	Default
`values`	`list[Any]`	The column's raw values (non-numeric entries are ignored).	required
`class_count`	`int`	Number of classes (clamped to at least 2).	`5`
`color_ramp`	`str`	A ramp name from `VECTOR_COLOR_RAMPS`.	`'viridis'`
`classification_scheme`	`str`	`"equal-interval"` or `"quantile"`.	`'equal-interval'`

Returns:

Type	Description
`list[dict[str, Any]]`	A list of `{"value": float, "color": str}` stops.

Raises:

Type	Description
`ValueError`	If `classification_scheme` is not supported.