Legend for the Layers

Legend is an important component for data visualization. In whitecanvas, you can automatically or manually create legends independent of the backend you are using.

Note

The legend is not supported in the vispy backend.

To create a legend, you can use the add_legend method. The layer names are used as the labels of the legend.

import numpy as np
from whitecanvas import new_canvas

x = np.linspace(-1, 1, 100)
canvas = new_canvas(backend="matplotlib")
canvas.add_line(x, x, name="y=x", color="gray")
canvas.add_line(x, x**2, name="y=x^2", color="blue")
canvas.add_line(x, x**3, name="y=x^3", color="red", style="--")

canvas.add_legend()
canvas.show()

You can explicitly specify the layers to be included in the legend. If a str is given, it is interpreted as the title.

import numpy as np
from whitecanvas import new_canvas

x = np.linspace(-1, 1, 100)
canvas = new_canvas(backend="matplotlib")
x1 = canvas.add_line(x, x, name="y=x", color="gray")
x2 = canvas.add_line(x, x**2, name="y=x^2", color="blue")
x3 = canvas.add_line(x, x**3, name="y=x^3", color="red", style="--")

canvas.add_legend(["odd functions", x1, x3])
canvas.show()

Legend location can be specified by the location argument.

import numpy as np
from whitecanvas import new_canvas

x = np.linspace(-1, 1, 100)
canvas = new_canvas(backend="matplotlib")
x1 = canvas.add_line(x, x, name="y=x", color="gray")
x2 = canvas.add_line(x, x**2, name="y=x^2", color="blue")
x3 = canvas.add_line(x, x**3, name="y=x^3", color="red", style="--")

canvas.add_legend(location="right_side_top")
canvas.show()