Добавить вертикальный слайдер с matplotlib

Question

Я хотел бы создать вертикальный слайдер вместо горизонтального слайдера с matplotlib.

Я нашел хороший пример на веб-странице matplotlib http://matplotlib.org/examples/widgets/slider_demo.html, но я не знаю, как перемещать ползунок по оси Y и менять метки ползунка. Я могу изменить положение оси, но не движение ползунка. Пример здесь:

import numpy as np 
import matplotlib.pyplot as plt 
from matplotlib.widgets import Slider, Button, RadioButtons 

fig, ax = plt.subplots() 
plt.subplots_adjust(left=0.25, bottom=0.25) 
t = np.arange(0.0, 1.0, 0.001) 
a0 = 5 
f0 = 3 
s = a0*np.sin(2*np.pi*f0*t) 
l, = plt.plot(t,s, lw=2, color='red') 
plt.axis([0, 1, -10, 10]) 

axcolor = 'lightgoldenrodyellow' 
axfreq = plt.axes([0.03, 0.25, 0.03, 0.65], axisbg=axcolor) 
axamp = plt.axes([0.08, 0.25, 0.03, 0.65], axisbg=axcolor) 
sfreq = Slider(axfreq, 'Freq', 0.1, 30.0, valinit=f0) 
samp = Slider(axamp, 'Amp', 0.1, 10.0, valinit=a0) 

def update(val): 
    amp = samp.val 
    freq = sfreq.val 
    l.set_ydata(amp*np.sin(2*np.pi*freq*t)) 
    fig.canvas.draw_idle() 
sfreq.on_changed(update) 
samp.on_changed(update) 

resetax = plt.axes([0.8, 0.025, 0.1, 0.04]) 
button = Button(resetax, 'Reset', color=axcolor, hovercolor='0.975') 
def reset(event): 
    sfreq.reset() 
    samp.reset() 
button.on_clicked(reset) 

rax = plt.axes([0.5, 0.025, 0.15, 0.15], axisbg=axcolor) 
radio = RadioButtons(rax, ('red', 'blue', 'green'), active=0) 
def colorfunc(label): 
    l.set_color(label) 
    fig.canvas.draw_idle() 
radio.on_clicked(colorfunc) 

plt.show() 

Answer 1

Это невозможно из коробки, потому что matplotlib.widgets.Slider реализация использует axvspan и axvline определить ползунок (который является patches.Polygon), и обновляет его в соответствии с горизонтальным предположением. Не слишком сложно написать собственный вертикальный слайдер с использованием горизонтального слайдера в качестве примера (вы также должны были бы подкласса от AxesWidget), но это нужно сделать самому.

Действует с matplotlib 2.0: Ниже приведен вертикальный слайдер; он работает так же, как и горизонтальный, за исключением того, что ... хорошо ... вертикально!

from matplotlib.widgets import AxesWidget 
import six 

class VertSlider(AxesWidget): 
    """ 
    A slider representing a floating point range. 

    For the slider to remain responsive you must maintain a 
    reference to it. 

    The following attributes are defined 
     *ax*  : the slider :class:`matplotlib.axes.Axes` instance 

     *val*  : the current slider value 

     *hline*  : a :class:`matplotlib.lines.Line2D` instance 
        representing the initial value of the slider 

     *poly*  : A :class:`matplotlib.patches.Polygon` instance 
        which is the slider knob 

     *valfmt* : the format string for formatting the slider text 

     *label*  : a :class:`matplotlib.text.Text` instance 
        for the slider label 

     *closedmin* : whether the slider is closed on the minimum 

     *closedmax* : whether the slider is closed on the maximum 

     *slidermin* : another slider - if not *None*, this slider must be 
        greater than *slidermin* 

     *slidermax* : another slider - if not *None*, this slider must be 
        less than *slidermax* 

     *dragging* : allow for mouse dragging on slider 

    Call :meth:`on_changed` to connect to the slider event 
    """ 
    def __init__(self, ax, label, valmin, valmax, valinit=0.5, valfmt='%1.2f', 
       closedmin=True, closedmax=True, slidermin=None, 
       slidermax=None, dragging=True, **kwargs): 
     """ 
     Create a slider from *valmin* to *valmax* in axes *ax*. 

     Additional kwargs are passed on to ``self.poly`` which is the 
     :class:`matplotlib.patches.Rectangle` which draws the slider 
     knob. See the :class:`matplotlib.patches.Rectangle` documentation 
     valid property names (e.g., *facecolor*, *edgecolor*, *alpha*, ...). 

     Parameters 
     ---------- 
     ax : Axes 
      The Axes to put the slider in 

     label : str 
      Slider label 

     valmin : float 
      The minimum value of the slider 

     valmax : float 
      The maximum value of the slider 

     valinit : float 
      The slider initial position 

     label : str 
      The slider label 

     valfmt : str 
      Used to format the slider value, fprint format string 

     closedmin : bool 
      Indicate whether the slider interval is closed on the bottom 

     closedmax : bool 
      Indicate whether the slider interval is closed on the top 

     slidermin : Slider or None 
      Do not allow the current slider to have a value less than 
      `slidermin` 

     slidermax : Slider or None 
      Do not allow the current slider to have a value greater than 
      `slidermax` 


     dragging : bool 
      if the slider can be dragged by the mouse 

     """ 
     AxesWidget.__init__(self, ax) 

     self.valmin = valmin 
     self.valmax = valmax 
     self.val = valinit 
     self.valinit = valinit 
     self.poly = ax.axhspan(valmin, valinit, 0, 1, **kwargs) 

     self.hline = ax.axhline(valinit, 0, 1, color='r', lw=1) 

     self.valfmt = valfmt 
     ax.set_xticks([]) 
     ax.set_ylim((valmin, valmax)) 
     ax.set_yticks([]) 
     ax.set_navigate(False) 

     self.connect_event('button_press_event', self._update) 
     self.connect_event('button_release_event', self._update) 
     if dragging: 
      self.connect_event('motion_notify_event', self._update) 
     self.label = ax.text(0.5, 1.03, label, transform=ax.transAxes, 
          verticalalignment='center', 
          horizontalalignment='center') 

     self.valtext = ax.text(0.5, -0.03, valfmt % valinit, 
           transform=ax.transAxes, 
           verticalalignment='center', 
           horizontalalignment='center') 

     self.cnt = 0 
     self.observers = {} 

     self.closedmin = closedmin 
     self.closedmax = closedmax 
     self.slidermin = slidermin 
     self.slidermax = slidermax 
     self.drag_active = False 

    def _update(self, event): 
     """update the slider position""" 
     if self.ignore(event): 
      return 

     if event.button != 1: 
      return 

     if event.name == 'button_press_event' and event.inaxes == self.ax: 
      self.drag_active = True 
      event.canvas.grab_mouse(self.ax) 

     if not self.drag_active: 
      return 

     elif ((event.name == 'button_release_event') or 
       (event.name == 'button_press_event' and 
       event.inaxes != self.ax)): 
      self.drag_active = False 
      event.canvas.release_mouse(self.ax) 
      return 

     val = event.ydata 
     if val <= self.valmin: 
      if not self.closedmin: 
       return 
      val = self.valmin 
     elif val >= self.valmax: 
      if not self.closedmax: 
       return 
      val = self.valmax 

     if self.slidermin is not None and val <= self.slidermin.val: 
      if not self.closedmin: 
       return 
      val = self.slidermin.val 

     if self.slidermax is not None and val >= self.slidermax.val: 
      if not self.closedmax: 
       return 
      val = self.slidermax.val 

     self.set_val(val) 

    def set_val(self, val): 
     xy = self.poly.xy 
     xy[1] = 0, val 
     xy[2] = 1, val 
     self.poly.xy = xy 
     self.valtext.set_text(self.valfmt % val) 
     if self.drawon: 
      self.ax.figure.canvas.draw_idle() 
     self.val = val 
     if not self.eventson: 
      return 
     for cid, func in six.iteritems(self.observers): 
      func(val) 

    def on_changed(self, func): 
     """ 
     When the slider value is changed, call *func* with the new 
     slider position 

     A connection id is returned which can be used to disconnect 
     """ 
     cid = self.cnt 
     self.observers[cid] = func 
     self.cnt += 1 
     return cid 

    def disconnect(self, cid): 
     """remove the observer with connection id *cid*""" 
     try: 
      del self.observers[cid] 
     except KeyError: 
      pass 

    def reset(self): 
     """reset the slider to the initial value if needed""" 
     if (self.val != self.valinit): 
      self.set_val(self.valinit)