如何将 ipywidget 滑块的默认位置更改为 matplotlib 图形的一侧？

Question

我正在寻找一种方法来更改 matplotlib 图右侧的垂直 IntSlider 的位置。这是代码：

from ipywidgets import interact, fixed, IntSlider
import numpy as np
from matplotlib import pyplot as plt

%matplotlib notebook

fig = plt.figure(figsize=(8,4))

xs = np.random.random_integers(0, 5000, 50)
ys = np.random.random_integers(0, 5000, 50)

ax = fig.add_subplot(111)
scat, = ax.plot(xs, ys, 'kx', markersize=1)
ax.grid(which='both', color='.25', lw=.1)
ax.set_aspect('equal'), ax.set_title('Rotate')

def rotate(theta, xs, ys):
    new_xs = xs * np.cos(np.deg2rad(theta)) - ys * np.sin(np.deg2rad(theta))
    new_xs -= new_xs.min()
    new_ys = xs * np.sin(np.deg2rad(theta)) + ys * np.cos(np.deg2rad(theta))
    new_ys -= new_ys.min()
    return new_xs, new_ys

def update_plot(theta, xs, ys):
    new_xs, new_ys = rotate(theta, xs, ys)
    scat.set_xdata(new_xs), scat.set_ydata(new_ys)
    ax.set_xlim(new_xs.min() - 500, new_xs.max() + 500)
    ax.set_ylim(new_ys.min() - 500, new_ys.max() + 500)

w = interact(update_plot, 
             theta=IntSlider(min=-180, max=180, step=5,value=0, orientation='vertical'), 
             xs=fixed(xs), 
             ys=fixed(ys))

这就是我所拥有的：

这就是我要的：

可能有一种非常简单的方法可以做到这一点，但我自己无法弄清楚。

我尝试将fig和interactive小部件放入然后用VBox包装，但它不起作用。VBoxIPython.display

在示例中找不到直接解决此问题的方法。

编辑1：

ipywidgets 提供了一个Output()捕获输出区域并在小部件上下文中使用它的类。

我会尝试弄清楚如何使用它。

这是对象： https://github.com/jupyter-widgets/ipywidgets/blob/master/ipywidgets/widgets/widget_output.py

Answer 1

您可以通过创建交互式小部件然后将其加载children到HBox. 交互式的子部件遵循此约定；(widget_0, widget_1 ..., output) 其中元组的最后一个成员是控制小部件的输出。您可以在声明之前或之后定义 HBox 的布局。阅读有关此处可用布局的更多信息。

以下解决方案有一些注意事项；图表最初可能不会显示，您可能必须在显示之前调整控件，其次，当使用%matplotlib notebook魔法时，控件可能会在更新时导致大量闪烁。除此之外，我认为这应该像你想要的那样工作；

from IPython.display import display
from ipywidgets import interactive, fixed, IntSlider, HBox, Layout
import numpy as np
import matplotlib.pylab as plt
%matplotlib notebook

def rotate(theta, xs, ys):
    new_xs = xs * np.cos(np.deg2rad(theta)) - ys * np.sin(np.deg2rad(theta))
    new_xs -= new_xs.min()
    new_ys = xs * np.sin(np.deg2rad(theta)) + ys * np.cos(np.deg2rad(theta))
    new_ys -= new_ys.min()
    return new_xs, new_ys

def update_plot(theta, xs, ys):
    fig = plt.figure(figsize=(8,4))
    ax = fig.add_subplot(111)
    scat, = ax.plot(xs, ys, 'kx', markersize=1)
    ax.grid(which='both', color='.25', lw=.1)
    ax.set_aspect('equal'), ax.set_title('Rotate')
    new_xs, new_ys = rotate(theta, xs, ys)
    scat.set_xdata(new_xs), scat.set_ydata(new_ys)
    ax.set_xlim(new_xs.min() - 500, new_xs.max() + 500)
    ax.set_ylim(new_ys.min() - 500, new_ys.max() + 500)

xs = np.random.randint(0, 5000, 50)
ys = np.random.randint(0, 5000, 50)
w = interactive(update_plot,
                theta=IntSlider(min=-180, max=180, step=5, value=0,orientation='vertical'), 
                xs=fixed(xs),
                ys=fixed(ys))

# Define the layout here.
box_layout = Layout(display='flex', flex_flow='row', justify_content='space-between', align_items='center')

display(HBox([w.children[1],w.children[0]], layout=box_layout))

更新：

这是 Jason Grout 在ipywidgets gitter中的解决方案。

from IPython.display import display, clear_output
from ipywidgets import interact, fixed, IntSlider, HBox, Layout, Output, VBox
import numpy as np 
import matplotlib.pyplot as plt
%matplotlib inline

def rotate(theta, xs, ys):
    new_xs = xs * np.cos(np.deg2rad(theta)) - ys * np.sin(np.deg2rad(theta))
    new_xs -= new_xs.min()
    new_ys = xs * np.sin(np.deg2rad(theta)) + ys * np.cos(np.deg2rad(theta))
    new_ys -= new_ys.min()
    return new_xs, new_ys

out = Output(layout={'width': '300px', 'height': '300px'})

def update_plot(change): 
    theta = change['new'] # new slider value 
    with out: 
        clear_output(wait=True)
        fig = plt.figure(figsize=(4,4))
        ax = fig.add_subplot(111)
        scat, = ax.plot(xs, ys, 'kx', markersize=1)
        ax.grid(which='both', color='.25', lw=.1)
        ax.set_aspect('equal'), ax.set_title('Rotate')
        new_xs, new_ys = rotate(theta, xs, ys) 
        scat.set_xdata(new_xs), scat.set_ydata(new_ys)
        ax.set_xlim(new_xs.min() - 500, new_xs.max() + 500)
        ax.set_ylim(new_ys.min() - 500, new_ys.max() + 500)
        plt.show()

xs = np.random.randint(0, 5000, 50) 
ys = np.random.randint(0, 5000, 50) 

slider = IntSlider(min=-180, max=180, step=5, value=0, orientation='vertical') 
slider.observe(update_plot, 'value')
update_plot({'new': slider.value}) 
display(HBox([out, slider]))