10

当我运行此示例并创建一个矩形选择时，如果我缩放或移动选择周围的绘图窗口会消失，直到我取消选择移动或缩放工具并再次单击绘图窗口。

我%matplotlib tkinter在 IPython 笔记本中使用。

我试图挂钩到缩放窗口并将矩形选择设置为可见时发生的限制更改：

def persist_rect(newlims):
    rs = toggle_selector.RS
    print(rs.visible)
    rs.set_visible(True)
    rs.update()

current_ax.callbacks.connect('xlim_changed', persist_rect)
current_ax.callbacks.connect('ylim_changed', persist_rect)

但这似乎没有任何作用。它甚至没有toggle_selector.RS.visible被设置为假。

我也一直在寻找RectangleSelector 的来源，但我没有看到任何启发性的东西。

我还发现，当我使用RectangleSelector.extents = new_extents. 修改时.extents，例如使用滑块小部件，所选区域会消失，直到我再次单击绘图。

如果按照@ImportanceOfBeingErnest 的建议RectangleSelector进行初始化，所有这些问题都会消失，但正如他们所说，这不是一个非常高效的解决方案。useblit=False

4

3 回答 3

5

如果我理解正确，矩形选择器应该在整个平移或缩放过程中保持可见。这可以通过不使用 blitting 来实现，

toggle_selector.RS = RectangleSelector(ax, ...,  useblit=False, ...)

这样做的副作用是绘图可能会变慢，具体取决于绘图的复杂性，因为如果没有 blitting，则在使用矩形选择器时会连续重绘完整的绘图。

于 2017-08-06T11:02:02.933 回答
5

为 s 添加回调draw_event：

def mycallback(event):
    if RS.active:
        RS.update()
plt.connect('draw_event', mycallback)

使RectangleSelector缩放或平移后保持不变，并兼容useblit=True.

例如，使用文档中的代码作为基础：

from __future__ import print_function
from matplotlib.widgets import RectangleSelector
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.widgets as widgets
import threading
import datetime as DT

def line_select_callback(eclick, erelease):
    'eclick and erelease are the press and release events'
    x1, y1 = eclick.xdata, eclick.ydata
    x2, y2 = erelease.xdata, erelease.ydata
    print("(%3.2f, %3.2f) --> (%3.2f, %3.2f)" % (x1, y1, x2, y2))
    print(" The button you used were: %s %s" % (eclick.button, erelease.button))

def toggle_selector(event):
    print(' Key pressed: {}'.format(event.key))
    if event.key in ['D', 'd'] and RS.active:
        print(' RectangleSelector deactivated.')
        RS.set_active(False)
        RS.set_visible(False)
        RS.update()
    if event.key in ['A', 'a'] and not RS.active:
        print(' RectangleSelector activated.')
        RS.set_active(True)
        RS.set_visible(True)
        RS.update()

def mycallback(event):
    if RS.active:
        # print('mycallback')
        RS.update()

# def persist_rect(newlims):
#     print('persist_rect')
#     RS.set_visible(True)
#     RS.update()

fig, ax = plt.subplots() 
# figtype = type(fig)
# figtype._draw = figtype.draw
# def mydraw(self, renderer):
#     print('figure.draw')
#     self._draw(renderer)
# figtype.draw = mydraw

N = 100000               
x = np.linspace(0.0, 10.0, N) 

RS = RectangleSelector(ax, line_select_callback,
                       drawtype='box', useblit=True,
                       button=[1, 3],  # don't use middle button
                       minspanx=5, minspany=5,
                       spancoords='pixels',
                       interactive=True)

plt.plot(x, +np.sin(.2*np.pi*x), lw=3.5, c='b', alpha=.7) 
plt.plot(x, +np.cos(.2*np.pi*x), lw=3.5, c='r', alpha=.5)
plt.plot(x, -np.sin(.2*np.pi*x), lw=3.5, c='g', alpha=.3)

plt.connect('key_press_event', toggle_selector)
plt.connect('draw_event', mycallback)
# ax.callbacks.connect('xlim_changed', persist_rect)
# ax.callbacks.connect('ylim_changed', persist_rect)

plt.show()

为什么mycallback有效但persist_rect无效？

如果你取消注释上面的注释掉的语句，你会得到一些打印输出，看起来像这样：

figure.draw
mycallback
figure.draw
mycallback
(4.09, -0.53) --> (8.15, 0.38)
 The button you used were: 1 1
persist_rect
persist_rect
figure.draw
mycallback
 Key pressed: q

请注意，persist_rect在之前调用figure.draw，而mycallback在之后调用。figure.draw不绘制RectangleSelection，但确实绘制了Rectangle用于背景的 。如此figure.draw晦涩难懂RectangleSelection。因此persist_rect暂时显示RectangleSelection，但无法持久。 mycallback有效，因为它是在 之后调用的figure.draw。

于 2017-08-16T22:25:50.323 回答
0

在RectangularSelector的源代码中，release 方法（第 2119 行）处理选择器的可见性

def _release(self, event):   
"""on button release event"""
    if not self.interactive:
        self.to_draw.set_visible(False)

子类 RectangleSelector 修改释放方法

class visibleRectangleSelector(RectangleSelector):
    def release(self, event):
        super(visibleRectangleSelector, self).release(event)
        self.to_draw.set_visible(True)
        self.canvas.draw()   ##updates canvas for new selection

使用文档示例的示例代码

from __future__ import print_function
"""
Do a mouseclick somewhere, move the mouse to some destination, release
the button.  This class gives click- and release-events and also draws
a line or a box from the click-point to the actual mouseposition
(within the same axes) until the button is released.  Within the
method 'self.ignore()' it is checked whether the button from eventpress
and eventrelease are the same.

"""
from matplotlib.widgets import RectangleSelector
import numpy as np
import matplotlib.pyplot as plt


class visibleRectangleSelector(RectangleSelector):
    def release(self, event):
        super(visibleRectangleSelector, self).release(event)
        self.to_draw.set_visible(True)
        self.canvas.draw() 


def line_select_callback(eclick, erelease):
    'eclick and erelease are the press and release events'
    x1, y1 = eclick.xdata, eclick.ydata
    x2, y2 = erelease.xdata, erelease.ydata
    print("(%3.2f, %3.2f) --> (%3.2f, %3.2f)" % (x1, y1, x2, y2))
    print(" The button you used were: %s %s" % (eclick.button,
                                                erelease.button))


def toggle_selector(event):
    print(' Key pressed.')
    if event.key in ['Q', 'q'] and toggle_selector.RS.active:
        print(' RectangleSelector deactivated.')
        toggle_selector.RS.set_active(False)
    if event.key in ['A', 'a'] and not toggle_selector.RS.active:
        print(' RectangleSelector activated.')
        toggle_selector.RS.set_active(True)


fig, current_ax = plt.subplots()  # make a new plotting range
N = 100000  # If N is large one can see
x = np.linspace(0.0, 10.0, N)  # improvement by use blitting!

plt.plot(x, +np.sin(.2 * np.pi * x), lw=3.5, c='b', alpha=.7)  # plot something
plt.plot(x, +np.cos(.2 * np.pi * x), lw=3.5, c='r', alpha=.5)
plt.plot(x, -np.sin(.2 * np.pi * x), lw=3.5, c='g', alpha=.3)

print("\n      click  -->  release")

# drawtype is 'box' or 'line' or 'none'
toggle_selector.RS = RectangleSelector(
    current_ax,
    line_select_callback,
    drawtype='box',
    useblit=False,
    button=[1, 3],  # don't use middle button
    minspanx=5,
    minspany=5,
    spancoords='pixels',
    interactive=True)
plt.connect('key_press_event', toggle_selector)
plt.show()
于 2017-08-15T19:26:51.817 回答