Question

我正在与pyqtgraph合作创建节点和边缘的交互式网络（最初来自this问题，所需的所有代码都来自here）。我在点击该节点时尝试更改节点及其邻居（边缘和其连接的其他节点）的颜色。下面的代码显示了如何获取被单击的节点及其边缘和连接的其他节点。现在，我不明白如何改变特定pyqtgraph散点图项的颜色。

在下面的代码中，我可以使用scatter.setPen()更改图表中所有节点的颜色，但将其应用于例如只有我点击的节点（pts[0].setPen()）不起作用。谁能告诉我如何更改明确定义的节点和边缘的颜色？

非常感谢任何帮助。

修改：

在kesumu的非常有用的提示和找到here和here的代码片段之后，我终于明白了。

代码：

    # -*- coding: utf-8 -*-
"""
Simple example of subclassing GraphItem.
"""

# https://groups.google.com/forum/#!topic/pyqtgraph/pTrem1RCKSw
# https://stackoverflow.com/questions/18867980/pyqtgraph-select-2d-region-of-graph-as-threshold-to-redraw-the-graph
# https://groups.google.com/forum/#!topic/pyqtgraph/pTrem1RCKSw
# https://groups.google.com/forum/#!topic/pyqtgraph/dqw_Lip8rNk

import initExample ## Add path to library (just for examples; you do not need this)

import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui
from pyqtgraph.Point import Point
import numpy as np


def MultiSelect(newLines, mypoint_index_all, mypoint_edges, mypoints_all_edges, allpoints_neighbornodes, symbolBrushs):
    mypoint_neighbornodes = list(set([e for tup in mypoint_edges for e in tup]))
    allpoints_neighbornodes.append(mypoint_neighbornodes)

    for myp_index in mypoint_index_all:
        symbolBrushs[myp_index] = pg.mkBrush(color=(255, 0, 0))
        for allmy_neighbornodes in allpoints_neighbornodes:
            for all_node in allmy_neighbornodes:
                symbolBrushs[all_node] = pg.mkBrush(color=(255, 0, 0))
            for myp_eges in mypoints_all_edges:
                for i in range(len(myp_eges)):
                    for j in range(len(adj)):
                        if np.array_equal(adj[j], myp_eges[i]):
                            break
                    index = j
                    newLines.itemset(index, (255, 0, 0, 255, 1))

    return newLines, symbolBrushs


class MyViewBox(pg.ViewBox):
    def mouseDragEvent(self, ev):
        if ev.button() == QtCore.Qt.RightButton:
            ev.ignore()
        else:
            pg.ViewBox.mouseDragEvent(self, ev)

        ev.accept()
        pos = ev.pos()
        self.dragPoint = None
        if ev.button() == QtCore.Qt.RightButton:
            if ev.isFinish():
                self.rbScaleBox.hide()
                self.ax = QtCore.QRectF(Point(ev.buttonDownPos(ev.button())), Point(pos))
                self.ax = self.childGroup.mapRectFromParent(self.ax)
                self.Coords =  self.ax.getCoords()
                self.getPointsInRect()
            else:
                self.updateScaleBox(ev.buttonDownPos(), ev.pos())

    def getPointsInRect(self):
        # Get the data from the Graphicsitem that are within scaleBox rectangle
        data = viewbx.allChildren()[2].data.tolist()
        rectangle_coordinates = self.Coords
        graph_nodes_x_coords = viewbx.allChildren()[2].getData()[0]
        graph_nodes_y_coords = viewbx.allChildren()[2].getData()[1]
        graph_nodes = zip(graph_nodes_x_coords, graph_nodes_y_coords)

        rect_x1 = rectangle_coordinates[0]
        rect_y1 = rectangle_coordinates[1]
        rect_x2 = rectangle_coordinates[2]
        rect_y2 = rectangle_coordinates[3]

        points_in_rect_list = []
        for tup in graph_nodes:
            point_x = tup[0]
            point_y = tup[1]
            if rect_x1 <= point_x <= rect_x2 and rect_y1 <= point_y <= rect_y2:
                points_in_rect_list.append(tup)

        self.changePointsColors(points_in_rect_list, data, graph_nodes_x_coords, graph_nodes_y_coords)

    def changePointsColors(self, pointslist, data, graph_nodes_x_coords, graph_nodes_y_coords):
        data_x = [tup[0] for tup in pointslist]
        data_y = [tup[1] for tup in pointslist]
        newPos = np.vstack([graph_nodes_x_coords, graph_nodes_y_coords]).transpose()
        newLines = lines.copy()
        symbolBrushs = [None] * len(data)

        if QtGui.QApplication.keyboardModifiers() == QtCore.Qt.ControlModifier:  # check if ctrl key is pressed
            self.symbolBrushs_allpoints_indx = g.symbolBrushs_allpoints_indx
            self.symbolBrushs_allpoints_neighbornodes = g.symbolBrushs_allpoints_neighbornodes
            self.mypoint_edges_allpoints = g.mypoint_edges_allpoints

        else:
            self.symbolBrushs_allpoints_indx = []
            self.symbolBrushs_allpoints_neighbornodes = []
            self.mypoint_edges_allpoints = []

        for x, y in zip(data_x, data_y):
            for tup in data:
                if x == tup[0] and y == tup[1]:
                    mypoint_indx = data.index(tup)
                    mypoint_edges = [tup for tup in g.data['adj'] if mypoint_indx in tup]

                    self.symbolBrushs_allpoints_indx.append(mypoint_indx)
                    self.mypoint_edges_allpoints.append(mypoint_edges)

                    mypoint_neighbornodes = list(set([e for tup in mypoint_edges for e in tup]))
                    self.symbolBrushs_allpoints_neighbornodes.append(mypoint_neighbornodes)

        newLines, symbolBrushs = MultiSelect(newLines=newLines, mypoint_index_all=self.symbolBrushs_allpoints_indx,
                               mypoint_edges=mypoint_edges, mypoints_all_edges=self.mypoint_edges_allpoints,
                               allpoints_neighbornodes=self.symbolBrushs_allpoints_neighbornodes, symbolBrushs=symbolBrushs)

        g.setData(pos=newPos, adj=adj, pen=newLines, size=1, symbol=symbols, pxMode=False, text=texts,
              symbolBrush=symbolBrushs)

        g.updateGraph()


class Graph(pg.GraphItem):
    def __init__(self):
        self.textItems = []
        pg.GraphItem.__init__(self)
        self.scatter.sigClicked.connect(self.clicked)
        self.symbolBrushs_allpoints_indx = []
        self.symbolBrushs_allpoints_neighbornodes = []
        self.mypoint_edges_allpoints = []

    def setData(self, **kwds):
        self.text = kwds.pop('text', [])
        self.data = kwds
        if 'pos' in self.data:
            npts = self.data['pos'].shape[0]
            self.data['data'] = np.empty(npts, dtype=[('index', int)])
            self.data['data']['index'] = np.arange(npts)
        self.setTexts(self.text)
        self.updateGraph()

    def setTexts(self, text):
        for i in self.textItems:
            i.scene().removeItem(i)
        self.textItems = []
        for t in text:
            item = pg.TextItem(t)
            self.textItems.append(item)
            item.setParentItem(self)

    def updateGraph(self):
        pg.GraphItem.setData(self, **self.data)
        for i,item in enumerate(self.textItems):
            item.setPos(*self.data['pos'][i])

    def mouseDragEvent(self, ev):
        ev.accept()
        pos = ev.pos()

        if ev.isStart():
            # We are already one step into the drag.
            # Find the point(s) at the mouse cursor when the button was first
            # pressed:
            pos = ev.buttonDownPos()
            pts = self.scatter.pointsAt(pos)
            if len(pts) == 0:
                ev.ignore()
                return
            self.dragPoint = pts[0]
            ind = pts[0].data()[0]
            self.dragOffset = self.data['pos'][ind] - pos
        if ev.isFinish():
            self.dragPoint = None
            return
        else:
            if self.dragPoint is None:
                ev.ignore()
                return

        ind = self.dragPoint.data()[0]
        self.data['pos'][ind] = ev.pos() + self.dragOffset
        self.updateGraph()
        ev.accept()

    def clicked(self, scatter, pts):
        # print(self)
        data_list = scatter.data.tolist()
        mypoint = [tup for tup in data_list if pts[0] in tup][0]
        mypoint_index = data_list.index(mypoint)
        mypoint_edges = [tup for tup in self.data['adj'] if mypoint_index in tup]
        mypoint_neighbornodes = list(set([e for tup in mypoint_edges for e in tup]))

        data = scatter.getData()
        newPos = np.vstack([data[0], data[1]]).transpose()
        newLines = lines.copy()
        symbolBrushs = [None] * len(data[0])

        if QtGui.QApplication.keyboardModifiers() == QtCore.Qt.ControlModifier:  # check if ctrl key is pressed
            self.symbolBrushs_allpoints_indx.append(mypoint_index)
            self.mypoint_edges_allpoints.append(mypoint_edges)
            self.mypoint_neighbornodes = list(set([e for tup in mypoint_edges for e in tup]))
            self.symbolBrushs_allpoints_neighbornodes.append(mypoint_neighbornodes)

            newLines, symbolBrushs = MultiSelect(newLines=newLines, mypoint_index_all=self.symbolBrushs_allpoints_indx,
                                     mypoint_edges=mypoint_edges, mypoints_all_edges=self.mypoint_edges_allpoints,
                                     allpoints_neighbornodes=self.symbolBrushs_allpoints_neighbornodes,
                                     symbolBrushs=symbolBrushs)

        else:
            self.symbolBrushs_allpoints_indx = []
            self.symbolBrushs_allpoints_neighbornodes = []
            self.mypoint_edges_allpoints = []

            self.symbolBrushs_allpoints_indx.append(mypoint_index)
            self.mypoint_edges_allpoints.append(mypoint_edges)
            self.mypoint_neighbornodes = list(set([e for tup in mypoint_edges for e in tup]))
            self.symbolBrushs_allpoints_neighbornodes.append(mypoint_neighbornodes)
            print(self.symbolBrushs_allpoints_indx)

            symbolBrushs[mypoint_index] = pg.mkBrush(color=(255, 0, 0))
            for neighbornode in mypoint_neighbornodes:
                symbolBrushs[neighbornode] = pg.mkBrush(color=(255, 0, 0))
            for i in range(len(mypoint_edges)):
                for j in range(len(adj)):
                    if np.array_equal(adj[j], mypoint_edges[i]):
                        break
                index = j
                newLines.itemset(index, (255, 0, 0, 255, 1))

        g.setData(pos=newPos, adj=adj, pen=newLines, size=1, symbol=symbols, pxMode=False, text=texts,
                  symbolBrush=symbolBrushs)

        self.updateGraph()


# Enable antialiasing for prettier plots
pg.setConfigOptions(antialias=True)
w = pg.GraphicsWindow()
w.setWindowTitle('pyqtgraph example: CustomGraphItem')
viewbx = MyViewBox()
w.addItem(viewbx)
viewbx.setAspectLocked()

g = Graph()
viewbx.addItem(g)

# Define positions of nodes
pos = np.array([
    [0,0],
    [10,0],
    [0,10],
    [10,10],
    [5,5],
    [15,5]
    ], dtype=float)

# Define the set of connections in the graph
adj = np.array([
    [0,1],
    [1,3],
    [3,2],
    [2,0],
    [1,5],
    [3,5],
    ])

# Define the symbol to use for each node (this is optional)
symbols = ['o','o','o','o','o','o']

# Define the line style for each connection (this is optional)
lines = np.array([
    (255,255,255,255,1),
    (255,255,255,255,2),
    (255,255,255,255,3),
    (255,255,255,255,2),
    (255,255,255,255,1),
    (255,255,255,255,4),
    ], dtype=[('red',np.ubyte),('green',np.ubyte),('blue',np.ubyte),('alpha',np.ubyte),('width',float)])

# Define text to show next to each symbol
texts = ["Point %d" % i for i in range(6)]

# Update the graph
g.setData(pos=pos, adj=adj, pen=lines, size=1, symbol=symbols, pxMode=False, text=texts)


# Start Qt event loop unless running in interactive mode or using pyside.
if __name__ == '__main__':
    import sys
    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        QtGui.QApplication.instance().exec_()

Answer 1

我不知道为什么ExecuteNonQuery或scatter.setPen(pens)无效。作为替代方案，您可以像这样使用scatter.setBrush(brushes)：

g.setData

这就是结果：

pyqtgraph在点击时更改节点及其边缘的颜色

1 个答案: