Question

我使用matplotlib中的矩形选择器来裁剪一些图像它可以打印我点击并释放的位置，但我无法保存它们的坐标数据。我应该怎么做才能保存那些我点击并作为变量发布的坐标数据？例如，在我运行代码之后，它只会打印类似（2.14，-0.62） - ＆gt;的内容。（5.86,0.74）。（2.14，-0.62）是我点击的点的坐标数据，（5.86,0.74）是我发布的点。但我希望我可以有一些变量来保存这两个坐标日期，如：xclick = 2.14，yclick = -0.62，xrelease = 5.86，yrelease = 0.74，但我找不到办法做到这一点。我知道x，y坐标可能保存在x1，y1，x2，y2中，但是当我想调用其中的四个时，它返回“name'x1'未定义”，它们也不在我的变量explorer中。< / p>

以下是来自matplotlib示例的代码：

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


def line_select_callback(eclick, erelease):
    print(eclick.xdata)
    '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=True,
                                   button=[1, 3],  # don't use middle button
                                   minspanx=5, minspany=5,
                                   spancoords='pixels',
                                   interactive=True,state_modifier_keys =     'extents')
plt.connect('key_press_event', toggle_selector)
plt.show()

非常感谢你！

Answer 1

变量x1，y1，x2和y2位于line_select_callback函数的本地范围内。您可以使用global语句将它们全局访问。

def line_select_callback(eclick, erelease):
    global x1, y1, x2, y2
    x1, y1 = eclick.xdata, eclick.ydata
    x2, y2 = erelease.xdata, erelease.ydata

或者您可以将它们分配到全局定义的列表

click = [None,None]
release = [None,None]

def line_select_callback(eclick, erelease):
    click[:] = eclick.xdata, eclick.ydata
    release[:] = erelease.xdata, erelease.ydata

我想从matplotlib矩形选择器

1 个答案: