matplotlib:从数据中删除数据时散点图不更新

Question

我有一个GUI，允许用户使用形状创建点集（例如，中心位于X、Y和直径D的圆，其中N个点X、Y、D和N是使用输入框输入的）。你知道吗

从生成的点集，我进入一个树状视图以及绘制点的入口。然后用户可以选择一个treeview条目来高亮显示绘图上的那些点。你知道吗

数据图很好（我用一个空白数据集初始化散点图，然后每次用户生成输入时向散点图添加数据）。我遇到的问题是，如果用户删除了数据（使用GUI中的delete按钮）。存储数据的字典(自我模式)更新正确，但由于某些原因，数据未从绘图中删除。你知道吗

我假设使用

self.scat = self.ptrnFig.scatter([], [], c="b", marker="o", s=40)

在plotAllPtrns（）函数中，会给我一个空的散点图（就像我初始化绘图时一样），我可以将数据集中剩余的点重新添加到散点图中，但这似乎不起作用。你知道吗

我还试着添加一个

self.scat.remove()

在plotAllPtrns（）的开头绘制一条直线，然后只打印最后一组用户定义的点，而不是表中剩余的所有点。你知道吗

import tkinter as tk
from tkinter import ttk
import numpy as np

from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
import matplotlib
from matplotlib.figure import Figure
matplotlib.use("TkAgg")


class MainGUI(tk.Tk):

    def __init__(self):
        tk.Tk.__init__(self)
        self.title('Title')
        self.geometry('750x500')

        for i in range(9):
            self.rowconfigure(i, weight=1)
            self.columnconfigure(i, weight=1)

        self.mydict = {}

        self.makeTable()
        self.initializePlot()
        self.makeWidgets()

    def makeWidgets(self):
        self.Labels = []
        self.Entries = []
        self.labText = [('X Location:'), ('Y Location:')]

        self.xGrid = 1
        self.yGrid = int(np.ceil(len(self.labText) / self.xGrid))
        i = 0
        for j in range(0, self.xGrid + 1, 2):
            for k in range(self.yGrid):
                if(i == len(self.labText)):
                    break
                else:
                    self.label = tk.Label(self, text=self.labText[i])
                    self.label.grid(column=j, row=k + 8, sticky='SW')
                    self.Labels.append(self.label)
                    self.entry = tk.Entry(self)
                    self.entry.insert(0, '0.0000')
                    self.entry.grid(column=j + 1, row=k + 8, sticky='NS')
                    self.Entries.append(self.entry)
                    i += 1

        self.addBtn = tk.Button(self, text='Add Entry', command=self.addEntry)
        self.addBtn.grid(column=self.xGrid + 1, row=self.yGrid + 9, sticky='NSEW')
        self.delBtn = tk.Button(self, text='Delete Entry', command=self.delEntry)
        self.delBtn.grid(column=self.xGrid, row=self.yGrid + 9, sticky='NSEW')

    def makeTable(self):
        tab_header = ['Pattern #', 'Description']
        self.tree = ttk.Treeview(self, columns=tab_header, height=5, show="headings")
        self.tree.grid(column=0, row=0, columnspan=2, rowspan=5, sticky='NSEW')
        self.tree.heading(tab_header[0], text=tab_header[0].title())
        self.tree.heading(tab_header[1], text=tab_header[1].title())
        self.tree.insert('', 'end', values=("", "(new)"))
        self.tree.bind("<ButtonRelease-1>", self.getPtrnTable)
        self.counter = 1

    def getPtrnTable(self, event):
        self.item = self.tree.identify_row(event.y)
        try:
            self.patNum = self.tree.item(self.item, 'values')[0]
        except IndexError:
            self.patNum = ''
        self.patternPlot()

    def addEntry(self):
        check = (len(self.tree.get_children()) == 1)
        self.description = "Location: " + self.Entries[0].get() + ", " + self.Entries[1].get()
        self.tree.insert('', 'end', values=(self.counter, self.description))
        newEntry = [float(self.Entries[0].get()), float(self.Entries[1].get())]
        patKey = 'pattern_' + str(self.counter - 1)
        self.mydict[patKey] = newEntry
        if(check == True):
            self.points = np.array(newEntry, ndmin=2)
        else:
            self.points = np.vstack((self.points, newEntry))
        self.counter += 1
        self.scat.set_offsets(self.points)
        self.patNum = ""
        print("mydict: ", self.mydict)
        self.patternPlot()

    def delEntry(self):
        treeCnt = len(self.tree.get_children())
        patKey = 'pattern_' + str(int(self.patNum) - 1)
        del self.mydict[patKey]
        items = self.tree.get_children()
        for i in range(int(self.patNum), treeCnt - 1):
            old_key = 'pattern_' + str(i)
            new_key = 'pattern_' + str(i - 1)
            self.mydict[new_key] = self.mydict.pop(old_key)
            self.tree.set(items[i], 'Description', self.tree.item(items[i + 1], 'values')[1])
        self.tree.delete(items[-1])
        self.patNum = ""
        self.patternPlot()
        print("mydict: ", self.mydict)

    def initializePlot(self):
        self.fig = Figure(figsize=(1, 1), dpi=100)
        self.ptrnFig = self.fig.add_subplot(111)
        self.ptrnFig.axis([-5, 5, -5, 5])
        self.ptrnFig.spines['left'].set_position('zero')
        self.ptrnFig.spines['bottom'].set_position('zero')
        self.ptrnFig.grid(True)
        self.canvas = FigureCanvasTkAgg(self.fig, self)
        self.canvas.draw()
        self.canvas.get_tk_widget().grid(column=2, row=0, columnspan=6, rowspan=5, sticky='NSEW')
        self.scat = self.ptrnFig.scatter([], [], c="b", marker="o")
        self.scat2 = self.ptrnFig.scatter([], [], c="#ff5733", marker="o")  # Orange Color

    def plotAllPtrns(self):
        self.scat = self.ptrnFig.scatter([], [], c="b", marker="o", s=40)
        self.scat2.remove()
        self.scat2 = self.ptrnFig.scatter([], [], c="#ff5733", marker="o")  # Orange Color

        for k, v in self.mydict.items():
            x = self.mydict[k][0]
            y = self.mydict[k][1]
            bolt = np.array([x, y], ndmin=2)
            self.scat.set_offsets(bolt)

        self.canvas.draw_idle()

    def patternPlot(self):
        # All data deleted - reinitialize plot
        if(len(self.tree.get_children()) == 1):
            plt.close(self.fig)
            self.initializePtrnPlot()
        # No specific entry selected - plot everything
        elif(self.patNum == ""):
            self.plotAllPtrns()
        # Specific entry chosen - highlight selected entry
        else:
            self.scat2.remove()
            self.scat2 = self.ptrnFig.scatter([], [], c="#ff5733", marker="o")  # Orange Color

            patKey = 'pattern_' + str(int(self.patNum) - 1)
            x = self.mydict[patKey][0]
            y = self.mydict[patKey][1]
            bolt = np.array([x, y], ndmin=2)

            self.scat2.set_offsets(bolt)
            self.canvas.draw_idle()


def main():
    MainGUI().mainloop()


if __name__ == '__main__':
    main()

我错过了什么？我觉得在删除一个数据集之后，清除散点并重新填充它（就像我简单地添加数据时一样）应该可以工作。你知道吗

更新： 根据要求，我添加了代码的最小工作版本。与上面描述的创建模式不同，它只是一个点。根据需要添加点，单击表中的点以在绘图上高亮显示它们，然后使用delete将它们从表和存储在其中的词典中删除。当一个点被删除时，绘图不会更新，我不知道为什么。你知道吗

谢谢。你知道吗

Answer 1

正如@Treizh和@ImportanceOfBeingErnes所指出的，我确实对自我保护. 这并不是问题的根源，但是我已经更新了代码的完整版本来改进这一点。我还缺少对delEntry（）函数中patternPlot（）函数的调用，因此这一点得到了纠正（尽管它没有解决打印问题）。你知道吗

我认为问题在于set_offsets（）在循环中使用时是如何工作的。原始代码循环遍历字典中的每个条目，并尝试将其添加到用于绘图的数据集。似乎发生了一些我无法解释的事情，使得从数据集中删除的数据得以保留（可能是对存储在散点中的数据的弱引用？）。为了解决这个问题，我堆叠了所有字典条目（因为它们始终都是Nx2数组），然后使用set\u offsets（）一次将整个数据集添加到散点图中。更正的delEntry（）和更新的plotAllPtrns（）函数是：

def delEntry(self):
    treeCnt = len(self.tree.get_children())
    patKey = 'pattern_' + str(int(self.patNum) - 1)
    del self.mydict[patKey]
    items = self.tree.get_children()
    for i in range(int(self.patNum), treeCnt - 1):
        old_key = 'pattern_' + str(i)
        new_key = 'pattern_' + str(i - 1)
        self.mydict[new_key] = self.mydict.pop(old_key)
        self.tree.set(items[i], 'Description', self.tree.item(items[i + 1], 'values')[1])
    self.tree.delete(items[-1])
    self.patNum = ""
    self.patternPlot()
    print("mydict: ", self.mydict)

def plotAllPtrns(self):
    self.scat.remove()
    self.scat = self.ptrnFig.scatter([], [], c="b", marker="o", s=40)
    self.scat2.remove()
    self.scat2 = self.ptrnFig.scatter([], [], c="#ff5733", marker="o")  # Orange Color

    patPlotData = np.vstack(([v for v in self.mydict.values()]))
    x = patPlotData[:, 0]
    y = patPlotData[:, 1]
    bolt = np.array([x, y], ndmin=2).T
    self.scat.set_offsets(bolt)

    self.canvas.draw_idle()

我确实不明白为什么即使清除了旧数据（使用scatter（[]，[]），也会保留在散点图中，或者为什么使用set_offsets（）一次添加所有数据似乎可以解决问题，但它是有效的。你知道吗

如果有人能解释的话，我很想更好地理解。谢谢。你知道吗

Answer 2

我将简单地按原样提供以下代码，它似乎可以从问题中解决问题。但请注意。。它在某些情况下会产生其他错误，因为self.patNum的定义和使用并不一致。我也修不好。你知道吗

import tkinter as tk
from tkinter import ttk
import numpy as np

from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
import matplotlib
from matplotlib.figure import Figure
matplotlib.use("TkAgg")


class MainGUI(tk.Tk):

    def __init__(self):
        tk.Tk.__init__(self)
        self.title('Title')
        self.geometry('750x500')

        for i in range(9):
            self.rowconfigure(i, weight=1)
            self.columnconfigure(i, weight=1)

        self.mydict = {}
        self.patNum = ''

        self.makeTable()
        self.initializePlot()
        self.makeWidgets()

    def makeWidgets(self):
        self.Labels = []
        self.Entries = []
        self.labText = [('X Location:'), ('Y Location:')]

        self.xGrid = 1
        self.yGrid = int(np.ceil(len(self.labText) / self.xGrid))
        i = 0
        for j in range(0, self.xGrid + 1, 2):
            for k in range(self.yGrid):
                if(i == len(self.labText)):
                    break
                else:
                    self.label = tk.Label(self, text=self.labText[i])
                    self.label.grid(column=j, row=k + 8, sticky='SW')
                    self.Labels.append(self.label)
                    self.entry = tk.Entry(self)
                    self.entry.insert(0, '0.0000')
                    self.entry.grid(column=j + 1, row=k + 8, sticky='NS')
                    self.Entries.append(self.entry)
                    i += 1

        self.addBtn = tk.Button(self, text='Add Entry', command=self.addEntry)
        self.addBtn.grid(column=self.xGrid + 1, row=self.yGrid + 9, sticky='NSEW')
        self.delBtn = tk.Button(self, text='Delete Entry', command=self.delEntry)
        self.delBtn.grid(column=self.xGrid, row=self.yGrid + 9, sticky='NSEW')

    def makeTable(self):
        tab_header = ['Pattern #', 'Description']
        self.tree = ttk.Treeview(self, columns=tab_header, height=5, show="headings")
        self.tree.grid(column=0, row=0, columnspan=2, rowspan=5, sticky='NSEW')
        self.tree.heading(tab_header[0], text=tab_header[0].title())
        self.tree.heading(tab_header[1], text=tab_header[1].title())
        self.tree.insert('', 'end', values=("", "(new)"))
        self.tree.bind("<ButtonRelease-1>", self.getPtrnTable)
        self.counter = 1

    def getPtrnTable(self, event):
        self.item = self.tree.identify_row(event.y)
        try:
            self.patNum = self.tree.item(self.item, 'values')[0]
        except IndexError:
            self.patNum = ''
        self.patternPlot()

    def addEntry(self):
        check = (len(self.tree.get_children()) == 1)
        self.description = "Location: " + self.Entries[0].get() + ", " + self.Entries[1].get()
        self.tree.insert('', 'end', values=(self.counter, self.description))
        newEntry = [float(self.Entries[0].get()), float(self.Entries[1].get())]
        patKey = 'pattern_' + str(self.counter - 1)
        self.mydict[patKey] = newEntry
        if(check == True):
            self.points = np.array(newEntry, ndmin=2)
        else:
            self.points = np.vstack((self.points, newEntry))
        self.counter += 1
        self.scat.set_offsets(self.points)
        self.patNum = ""
        print("mydict: ", self.mydict)
        self.patternPlot()

    def delEntry(self):
        treeCnt = len(self.tree.get_children())
        if self.patNum:
            patKey = 'pattern_' + str(int(self.patNum) - 1)
            del self.mydict[patKey]
            items = self.tree.get_children()
            for i in range(int(self.patNum), treeCnt - 1):
                old_key = 'pattern_' + str(i)
                new_key = 'pattern_' + str(i - 1)
                self.mydict[new_key] = self.mydict.pop(old_key)
                self.tree.set(items[i], 'Description', self.tree.item(items[i + 1], 'values')[1])
            self.tree.delete(items[-1])
            print("mydict: ", self.mydict)
            self.plotAllPtrns()

    def initializePlot(self):
        self.fig = Figure(figsize=(1, 1), dpi=100)
        self.ptrnFig = self.fig.add_subplot(111)
        self.ptrnFig.axis([-5, 5, -5, 5])
        self.ptrnFig.spines['left'].set_position('zero')
        self.ptrnFig.spines['bottom'].set_position('zero')
        self.ptrnFig.grid(True)
        self.canvas = FigureCanvasTkAgg(self.fig, self)
        self.canvas.draw()
        self.canvas.get_tk_widget().grid(column=2, row=0, columnspan=6, rowspan=5, sticky='NSEW')
        self.scat = self.ptrnFig.scatter([], [], c="b", marker="o")
        self.scat2 = self.ptrnFig.scatter([], [], c="#ff5733", marker="o")  # Orange Color

    def plotAllPtrns(self):
        print(self.mydict)
        self.scat.remove()
        self.scat = self.ptrnFig.scatter([], [], c="b", marker="o", s=40)
        self.scat2.remove()
        self.scat2 = self.ptrnFig.scatter([], [], c="#ff5733", marker="o")  # Orange Color

        xy = []
        for k, v in self.mydict.items():
            xy.append([self.mydict[k][0], self.mydict[k][1]])
        if xy:
            self.scat.set_offsets(xy)
        self.canvas.draw_idle()

    def patternPlot(self):
        print(self.tree.get_children())
        # All data deleted - reinitialize plot
        if(len(self.tree.get_children()) == 1):
            print("One Child")
        # No specific entry selected - plot everything
        elif(self.patNum == ""):
            self.plotAllPtrns()
        # Specific entry chosen - highlight selected entry
        else:
            self.scat2.remove()
            self.scat2 = self.ptrnFig.scatter([], [], c="#ff5733", marker="o")  # Orange Color

            patKey = 'pattern_' + str(int(self.patNum) - 1)
            x = self.mydict[patKey][0]
            y = self.mydict[patKey][1]
            bolt = np.array([x, y], ndmin=2)

            self.scat2.set_offsets(bolt)
            self.canvas.draw_idle()


def main():
    MainGUI().mainloop()


if __name__ == '__main__':
    main()