Legend

plotynium.legends.Legend

Legend(color_mapping=None, symbol_mapping=None, scheme=None, square_size=15, symbol_size=5, fill=None, fill_opacity=1.0, stroke=None, stroke_opacity=1.0, stroke_width=1.0, font_size=12, width=240, height=50, margin_top=21, margin_left=15, margin_bottom=21, margin_right=15)

Special mark which has its own definition for making a legend. Legend is located on top of the main canvas where all other marks are applied. Given the value of color_mapping and symbol_mapping arguments, this class takes decision to know if the legend should be continuous, discrete with squares or discrete with symbols.

Parameters:

Name	Type	Description	Default
color_mapping	list[tuple[str, str]] | None	List of pairs (label, color)	None
symbol_mapping	list[tuple[str, str]] | None	List of pairs (label, symbol path)	None
scheme	ColorScheme | None	Color scheme	None
square_size	int	Square_size (only for discrete legend)	15
symbol_size	int	Symbol size (only for symbol legend)	5
fill	str | None	Fill color for text	None
fill_opacity	float	Fill opacity	1.0
stroke	str | None	Stroke color for text	None
stroke_opacity	float	Stroke opacity	1.0
stroke_width	float	Stroke width (only for continuous legend)	1.0
font_size	int	Font size for text	12
width	int	Width size	240
height	int	Height size	50
margin_top	int	Margin top value	21
margin_left	int	Margin left value	15
margin_bottom	int	Margin bottom value	21
margin_right	int	Margin right value	15

Source code in plotynium/legends/__init__.py

def __init__(
    self,
    color_mapping: list[tuple[str, str]] | None = None,
    symbol_mapping: list[tuple[str, str]] | None = None,
    scheme: ColorScheme | None = None,
    square_size: int = 15,
    symbol_size: int = 5,
    fill: str | None = None,
    fill_opacity: float = 1.0,
    stroke: str | None = None,
    stroke_opacity: float = 1.0,
    stroke_width: float = 1.0,
    font_size: int = 12,
    width: int = 240,
    height: int = 50,
    margin_top: int = 21,
    margin_left: int = 15,
    margin_bottom: int = 21,
    margin_right: int = 15,
):
    Mark.__init__(self)
    self._color_mapping = color_mapping or [
        (str(x), "none") for x in d3.ticks(0, 1, 10)
    ]
    self._symbol_mapping = symbol_mapping or []
    self._scheme = scheme
    self._square_size = square_size
    self._symbol_size = symbol_size
    self._fill = Constant(fill or "currentColor")
    self._fill_opacity = fill_opacity
    self._stroke = Constant(stroke or "currentColor")
    self._stroke_opacity = stroke_opacity
    self._stroke_width = stroke_width
    self._font_size = font_size
    self._properties = LegendProperties.new(
        width,
        height,
        margin_top,
        margin_left,
        margin_bottom,
        margin_right,
    )

properties property

properties

Returns its properties

Returns:

Type	Description
LegendProperties	Own properties

apply

apply(svg, ctx)

Adds a legend on SVG content.

Parameters:

Name	Type	Description	Default
svg	Selection	SVG Content	required
ctx	Context	Context	required

Source code in plotynium/legends/__init__.py

def apply(self, svg: Selection, ctx: Context):
    """
    Adds a legend on SVG content.

    Parameters
    ----------
    svg : Selection
        SVG Content
    ctx : Context
        Context
    """
    # Updates attributes from context
    self._properties = ctx.legend_properties
    self._font_size = ctx.font_size
    self._scheme = (
        self._scheme
        or ctx.color_scheme
        or default_colorscheme(len(self._color_mapping))
    )

    # Adds the legend on the SVG given arguments
    if len(self._symbol_mapping) > 0:
        self.symbol_legend(svg)
    elif len(self._color_mapping) > 10:
        self.continuous_color_legend(svg)
    else:
        self.discrete_color_legend(svg)