在 matplotlib 中水平显示单选按钮

Question

我正在使用matplotlib.widgets 在我的小部件中创建单选按钮，即将出现的按钮垂直堆叠，我希望它们水平堆叠。

MVCE：

import matplotlib.pyplot as plt
from matplotlib.widgets import RadioButtons
plt.subplots_adjust(left=0.2)
rax = plt.axes([0.5,0.05,0.1,0.1])
radio =  RadioButtons(rax ,['1','2','3'], active=0, activecolor='blue' )
plt.show()

正如您在此示例中看到的那样，您可以获得这样的单选按钮 ,

我想知道有没有办法水平堆叠这些单选按钮。

Answer 1

目前正在尝试在PR #13374 中向RadioButtons 引入orientation 参数；这还没有最终确定。

正如我在此 PR 中所评论的，另一种选择是对按钮使用散点图。下面展示了我如何想象这个实现。与通常的按钮相比，有两个主要增强功能：

• 单选按钮始终为圆形，与轴的大小无关。
• 它们可以任意对齐，尤其是水平对齐。

这是通过在内部创建一个图例来实现的，该图例具有所有必需的选项。 Legend 的任何有效参数也可用于按钮。

import matplotlib.pyplot as plt
from matplotlib.widgets import AxesWidget, RadioButtons

class MyRadioButtons(RadioButtons):

    def __init__(self, ax, labels, active=0, activecolor='blue', size=49,
                 orientation="vertical", **kwargs):
        """
        Add radio buttons to an `~.axes.Axes`.
        Parameters
        ----------
        ax : `~matplotlib.axes.Axes`
            The axes to add the buttons to.
        labels : list of str
            The button labels.
        active : int
            The index of the initially selected button.
        activecolor : color
            The color of the selected button.
        size : float
            Size of the radio buttons
        orientation : str
            The orientation of the buttons: 'vertical' (default), or 'horizontal'.
        Further parameters are passed on to `Legend`.
        """
        AxesWidget.__init__(self, ax)
        self.activecolor = activecolor
        axcolor = ax.get_facecolor()
        self.value_selected = None

        ax.set_xticks([])
        ax.set_yticks([])
        ax.set_navigate(False)

        circles = []
        for i, label in enumerate(labels):
            if i == active:
                self.value_selected = label
                facecolor = activecolor
            else:
                facecolor = axcolor
            p = ax.scatter([],[], s=size, marker="o", edgecolor='black',
                           facecolor=facecolor)
            circles.append(p)
        if orientation == "horizontal":
            kwargs.update(ncol=len(labels), mode="expand")
        kwargs.setdefault("frameon", False)    
        self.box = ax.legend(circles, labels, loc="center", **kwargs)
        self.labels = self.box.texts
        self.circles = self.box.legendHandles
        for c in self.circles:
            c.set_picker(5)
        self.cnt = 0
        self.observers = {}

        self.connect_event('pick_event', self._clicked)


    def _clicked(self, event):
        if (self.ignore(event) or event.mouseevent.button != 1 or
            event.mouseevent.inaxes != self.ax):
            return
        if event.artist in self.circles:
            self.set_active(self.circles.index(event.artist))

把它当作

plt.subplots_adjust(left=0.2)
rax = plt.axes([0.5,0.05,0.4,0.07])
radio =  MyRadioButtons(rax ,['1','2','3'], active=0, activecolor='crimson',
                        orientation="horizontal")

plt.show()

或者

rax = plt.axes([0.2,0.5,0.25,0.1])
radio =  MyRadioButtons(rax ,["AA", "BB", "CC", "DD"], ncol=2)

Answer 2

由于 stackexchange 不希望将其作为编辑， 这是来自@ImportanceOfBeingErnest 的上述答案的更新版本，适用于最近的 matplotlib 版本（例如 >= v3.3）

import matplotlib.pyplot as plt
from matplotlib.widgets import AxesWidget, RadioButtons
from matplotlib import cbook

class MyRadioButtons(RadioButtons):

    def __init__(self, ax, labels, active=0, activecolor='blue', size=49,
                 orientation="vertical", **kwargs):
        """
        Add radio buttons to an `~.axes.Axes`.
        Parameters
        ----------
        ax : `~matplotlib.axes.Axes`
            The axes to add the buttons to.
        labels : list of str
            The button labels.
        active : int
            The index of the initially selected button.
        activecolor : color
            The color of the selected button.
        size : float
            Size of the radio buttons
        orientation : str
            The orientation of the buttons: 'vertical' (default), or 'horizontal'.
        Further parameters are passed on to `Legend`.
        """
        AxesWidget.__init__(self, ax)
        self.activecolor = activecolor
        axcolor = ax.get_facecolor()
        self.value_selected = None

        ax.set_xticks([])
        ax.set_yticks([])
        ax.set_navigate(False)

        circles = []
        for i, label in enumerate(labels):
            if i == active:
                self.value_selected = label
                facecolor = activecolor
            else:
                facecolor = axcolor
            p = ax.scatter([],[], s=size, marker="o", edgecolor='black',
                           facecolor=facecolor)
            circles.append(p)
        if orientation == "horizontal":
            kwargs.update(ncol=len(labels), mode="expand")
        kwargs.setdefault("frameon", False)    
        self.box = ax.legend(circles, labels, loc="center", **kwargs)
        self.labels = self.box.texts
        self.circles = self.box.legendHandles
        for c in self.circles:
            c.set_picker(5)
        
        self._observers = cbook.CallbackRegistry()
        
        self.connect_event('pick_event', self._clicked)


    def _clicked(self, event):
        if (self.ignore(event) or event.mouseevent.button != 1 or
            event.mouseevent.inaxes != self.ax):
            return
        if event.artist in self.circles:
            self.set_active(self.circles.index(event.artist))

把它当做

plt.subplots_adjust(left=0.2)
rax = plt.axes([0.5,0.05,0.4,0.07])
radio =  MyRadioButtons(rax ,['1','2','3'], active=0, activecolor='crimson',
                        orientation="horizontal")

plt.show()