如何通过单击小部件按钮将所有小部件值设置为默认值？

Question

在模拟中使用几个改变一些属性的滑块，我想创建一个 ipywidgets.Button 将所有滑块值设置为一些默认值，有人知道怎么做吗？

from ipywidgets import FloatSlider, IntSlider, IntText, Button

A = FloatSlider(value=4, min=-10, max=20, step=0.1)
B = IntSlider(value=2, min=0, max=8, step=2)
C = IntText()

default_value_button = Button(description='click to set default values')

...

#I want this button to set specific values for A,B,C
#I need its action to be:

    A.set_state('value') = 3.7
    B.set_state('value') = 4
    C.set_state('value') = 547

...

display(A,B,C,default_value_button)

点击按钮时需要设置默认值：

here's how it must look like

提前感谢您的关注！

Answer 1

这是一个简单的实现，只需为小部件设置一个default_value 属性，并在创建它们时将这些小部件编译成一个列表。

这样做的一个问题是，如果您将这些小部件连接到交互功能，那么将值设置为默认值也会导致交互功能触发。这可能是您想要的，也可能不是！

from ipywidgets import *

A = FloatSlider(value=4, min=-10, max=20, step=0.1)
B = IntSlider(value=2, min=0, max=8, step=2)
C = IntText()

A.default_value = 3.7
B.default_value = 4
C.default_value = 547

defaulting_widgets = [A,B,C]

default_value_button = Button(description='click to set default values')

def set_default(button):
    for widget in defaulting_widgets:
        widget.value = widget.default_value

default_value_button.on_click(set_default)

display(A,B,C,default_value_button)

Answer 2

import numpy as np
from ipywidgets import *
from matplotlib import cm
import matplotlib.pylab as plt
from mpl_toolkits.mplot3d import Axes3D
from mpl_toolkits.mplot3d import axes3d    

def hist_3D(xdata, ydata, xtitle='X',ytitle='Y'):
    SQUARE_BIN_NUMBER = IntSlider(description="bins" ,min=5, max=40, value=20)
    AZIM              = IntSlider(description="azimuth", min=-180, max=180, value=-60, layout=widgets.Layout(width='600px'))
    ELEV              = IntSlider(description="elevation", min=-90, max=90, value=30, layout=widgets.Layout(height='400px'), orientation='vertical')
    VU                = Dropdown (options=[('X histogram', 1), ('Y histogram', 2), ('XY colored', 3), ('Random view', 4)],
                              value=4, description='options :')
    SHADE             = Checkbox (description="shade", value=True)
    DEFAULT_VALUE_BUTTON = Button(description='default values')

    SQUARE_BIN_NUMBER.default_value = 20
    AZIM.default_value = -60
    ELEV.default_value = 30
    VU.default_value = 4
    SHADE.default_value = True

    defaulting_widgets = [SQUARE_BIN_NUMBER,AZIM,ELEV,VU,SHADE]
    def run(square_bin_number, azim, elev, vu=None, shade=True):
        if(vu == 1): azim, elev, shade = -90, 0, True
        elif(vu == 2): azim, elev, shade = 0, 0, False
        elif(vu == 3): azim, elev, shade = -90, 90, True

        x = np.array(xdata)   #turn x,y data into numpy arrays
        y = np.array(ydata)

        fig = plt.figure(figsize=(10,7))          #create a canvas, tell matplotlib it's 3d
        ax = fig.add_subplot(111, projection='3d')

        #make histogram stuff - set bins - I choose 20x20 because I have a lot of data
        hist, xedges, yedges = np.histogram2d(x, y, bins=(square_bin_number, square_bin_number))
        xpos, ypos = np.meshgrid(xedges[:-1]+xedges[1:], yedges[:-1]+yedges[1:], indexing='ij')
        #attenetion : meshgrid(indexing must be 'ij' and it's 'xy' by default)

        xpos = xpos.flatten()/2.
        ypos = ypos.flatten()/2.
        zpos = np.zeros_like (xpos)

        dx = xedges [1] - xedges [0]
        dy = yedges [1] - yedges [0]
        dz = hist.flatten()

        cmap = cm.get_cmap('jet') # Get desired colormap - you can change this!
        max_height = np.max(dz)   # get range of colorbars so we can normalize
        min_height = np.min(dz)
        # scale each z to [0,1], and get their rgb values
        rgba = [cmap((k-min_height)/max_height) for k in dz]

        ax.bar3d(xpos, ypos, zpos, dx, dy, dz, color=rgba, zsort='average', shade=shade)
        ax.view_init(azim=azim, elev=elev)

        plt.xlabel(xtitle)
        plt.ylabel(ytitle)
        # plt.savefig("Your_title_goes_here")
        plt.show()

    def set_default(button):
        for widget in defaulting_widgets:
            widget.value = widget.default_value

    DEFAULT_VALUE_BUTTON.on_click(set_default)

    out = interactive_output(run, {'vu':VU, 'square_bin_number':SQUARE_BIN_NUMBER,
                                   'azim':AZIM, 'elev':ELEV, 'shade':SHADE})

    display(VU, HBox([out, ELEV]), VBox([AZIM, HBox([SQUARE_BIN_NUMBER, SHADE])]), 
            DEFAULT_VALUE_BUTTON)

A = np.random.multivariate_normal([0,0], np.identity(2), size=10000)

x = A[:,0]
y = A[:,1]

hist_3D(x,y)