图例

此示例展示了使用枚举 LegendLocation 中包含的不同位置值，在图表上放置图例的不同方式。图例可以根据标题、形状和方向来定义。此图表显示了正弦和余弦曲线。

详细信息

Bokeh API:

bokeh.core.enums.LegendLocation, bokeh.models.ColumnDataSource, bokeh.models.DataRange1d, bokeh.models.Plot, bokeh.models.Legend

更多信息:

图例样式

关键词:

正弦，余弦，π， linspace，LegendLocation

from numpy import cos, linspace, pi, sin

from bokeh.core.enums import LegendLocation
from bokeh.io import show
from bokeh.models import (ColumnDataSource, DataRange1d, Legend, Line, LinearAxis,
                          PanTool, Plot, SaveTool, Scatter, WheelZoomTool)

x = linspace(-2*pi, 2*pi, 400)
y = sin(x)
y2 = cos(x)

source = ColumnDataSource(data=dict(x=x, y=y, y2=y2))

xdr = DataRange1d()
ydr = DataRange1d()

plot = Plot(
    x_range=xdr,
    y_range=ydr,
    width=1000,
    height=1000,
    min_border=0,
    toolbar_location=None,
    background_fill_color="#F0F0F0",
    border_fill_color="lightgray",
)

line_glyph = Line(x="x", y="y", line_color="navy", line_width=2, line_dash="dashed")
line = plot.add_glyph(source, line_glyph)
circle = Scatter(x="x", y="y2", size=6, line_color="red", fill_color="orange", fill_alpha=0.6)
circle = plot.add_glyph(source, circle)

pan = PanTool()
wheel_zoom = WheelZoomTool()
preview_save = SaveTool()

plot.add_tools(pan, wheel_zoom, preview_save)

# Add axes (Note it's important to add these before adding legends in side panels)
plot.add_layout(LinearAxis(), "below")
plot.add_layout(LinearAxis(), "left")
plot.add_layout(LinearAxis(), "right")

def add_legend(location, orientation, side, background_fill_color="#FFFFFF"):
    legend = Legend(
        items=[("line", [line]), ("circle", [circle])],
        location=location,
        orientation=orientation,
        border_line_color="black",
        background_fill_color=background_fill_color,
        title=f"Legend at\n{location!r}\n{orientation!r}\n{side!r}",
    )
    plot.add_layout(legend, side)

# Add legends in names positions e.g. "top_right", "top_left" (see plot for all)
for location in LegendLocation:
    # redundant positions get a different background color and a vertical orientation to show ambiguity
    if "_" not in location:
        background_fill_color = "#999999"
        orientation = "vertical"
    else:
        background_fill_color ="#CCCCCC"
        orientation = "horizontal"
    add_legend(location, orientation, "center", background_fill_color=background_fill_color)

# Add legend at fixed positions
add_legend((150, 50), "horizontal", "center")

# Add legend in side panels
add_legend("center_left", "horizontal", "above")
add_legend("center", "horizontal", "below")
add_legend("center", "vertical", "left")
add_legend("bottom_center", "vertical", "right")

show(plot)