第一次单击并调用on_clicked()

时间:2019-06-17 21:56:56

标签: python matplotlib plot widget interactive

我正在建立一个类,该类创建带有一些标记(X,Y)的直线的简单XY图。

这个想法是让用户可以选择通过拖动点来更新线。

我添加了一个“重置”按钮,该按钮应该将行恢复为原始值。

如果我拖动一个点并单击“重置”按钮,则可以正常工作,但是如果 尝试再次拖动一个点,按钮无响应。

我对matplotlib小部件还很陌生,我肯定缺少明显的东西...

请注意,我尝试使用不同的后端,也尝试使用(%matplotlib notebook)在笔记本单元内部

这是我的“ Path”类的代码:

import matplotlib.pyplot as plt
from matplotlib.widgets import Button
import matplotlib as mpl
import numpy as np
from copy import copy

class Path(object):

def __init__(self, xcoords, ycoords):

    self.xcoords = xcoords
    self.ycoords = ycoords
    self.original_xcoords = copy(xcoords)
    self.original_ycoords = copy(ycoords)
    self.pind = None  # active point
    self.epsilon = 5  # max pixel distance

    # figure.subplot.right
    mpl.rcParams['figure.subplot.right'] = 0.8

    # set up a plot
    self.fig, self.ax1 = plt.subplots(1, 1, figsize=(9.0, 8.0), sharex=True)

    self.ax1.plot(self.xcoords, self.ycoords, 'k--', label='original')

    self.l, = self.ax1.plot(self.xcoords, self.ycoords,
        color='k', linestyle='none',
        marker='o', markersize=8)

    self.m, = self.ax1.plot(self.xcoords, self.ycoords, 'r-')

    self.ax1.set_yscale('linear')
    self.ax1.legend(loc=4, prop={'size': 10})

    self.axres = plt.axes([0.84, 0.8-((self.original_xcoords.shape[0])*0.05), 0.12, 0.02])
    self.bres = Button(self.axres, 'Test')
    self.bres.on_clicked(self.reset)

    self.fig.canvas.mpl_connect('button_press_event', self.button_press_callback)
    self.fig.canvas.mpl_connect('button_release_event', self.button_release_callback)
    self.fig.canvas.mpl_connect('motion_notify_event', self.motion_notify_callback)

    plt.show()

def reset(self, event):
    """ Reset the values """
    self.xcoords = self.original_xcoords
    self.ycoords = self.original_ycoords
    self.l.set_xdata(self.xcoords)
    self.m.set_xdata(self.xcoords)
    self.l.set_ydata(self.ycoords)
    self.m.set_ydata(self.ycoords)
    plt.draw()

def button_press_callback(self, event):
    if event.inaxes is None:
        return
    if event.button != 1:
        return
    self.pind = self.get_ind_under_point(event)

def button_release_callback(self, event):
    if event.button != 1:
        return
    self.pind = None

def get_ind_under_point(self, event):
    """
       Get the index of the vertex under point if within epsilon tolerance
    """
    tinv = self.ax1.transData
    xr = np.reshape(self.xcoords, (np.shape(self.xcoords)[0], 1))
    yr = np.reshape(self.ycoords, (np.shape(self.ycoords)[0], 1))
    xy_vals = np.append(xr, yr, 1)
    xyt = tinv.transform(xy_vals)
    xt, yt = xyt[:, 0], xyt[:, 1]
    d = np.hypot(xt - event.x, yt - event.y)
    indseq, = np.nonzero(d == d.min())
    ind = indseq[0]

    if d[ind] >= self.epsilon:
        ind = None

    return ind

def motion_notify_callback(self, event):
    'on mouse movement'
    if self.pind is None:
        return
    if event.inaxes is None:
        return
    if event.button != 1:
        return

    self.ycoords[self.pind] = event.ydata
    self.xcoords[self.pind] = event.xdata
    self.l.set_xdata(self.xcoords)
    self.m.set_xdata(self.xcoords)
    self.l.set_ydata(self.ycoords)
    self.m.set_ydata(self.ycoords)
    self.fig.canvas.draw_idle()


x = np.array([1,2,3,4])
y = np.array([5, 6, 2, 3])

#%matplotlib notebook
A = Path(x, y)

2 个答案:

答案 0 :(得分:1)

问题的最小示例是:

import numpy as np

a = np.array([1,2,3])
b = a

b[1] = 1000
print(a)

它会打印[1, 1000, 3],即使您似乎只修改了ba也被修改了。这是因为它们 是相同的数组。

因此,与其复制对同一数组的引用,不如复制该数组或仅使用其值。

import numpy as np

a = np.array([1,2,3])
b = np.copy(a)

b[1] = 1000
print(a)

就您而言,

self.xcoords[:] = self.original_xcoords
self.ycoords[:] = self.original_ycoords

self.xcoords = np.copy(self.original_xcoords)
self.ycoords = np.copy(self.original_ycoords)

答案 1 :(得分:0)

长话短说:您应该更改重置功能:

self.xcoords = np.copy(self.original_xcoords)
self.ycoords = np.copy(self.original_ycoords)

简而言之,Python中的所有变量都类似于对象的链接。当您写a = 5时,a链接到对象“ 5”,当您写b = a时,b链接为“ 5”,a。您的self.coordsself.original_coords也会发生相同的情况。您必须复制它们以使它们链接到不同的对象。在第一次调用reset()函数之后,它们链接到同一对象。 您在此处保存了错误的坐标,因此自此以来,您的self.xcoordsself.original_coords对象已链接到同一对象