问题
I'm working with pyqtgraph to create an interactive network of nodes and edges (initially from this question, all code needed comes from here). I'm trying to change the color of a node and its neighbors (edges and other nodes it is connected to) when clicking on that node. The code below shows how to get the node which was clicked as well as its edges and other nodes it is connected to. Now, I don't understand how one can change the color of specific pyqtgraph scatterplot items.
In the code below, I can change the color of all nodes of the graph with scatter.setPen(), but applying it to e.g. only the node I clicked on (pts[0].setPen()) does not work. Can anyone please tell me how to change the color of explicitly defined nodes and edges?
Any help would be very much appreciated.
Edit:
After the very helpful hints from kesumu and the code snippets found here and here, I finally got it working.
Code:
# -*- 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_()
回答1:
I don't know why scatter.setPen(pens) or scatter.setBrush(brushes) is not working.
As an alternative, you can use g.setData like this:
def clicked(self, scatter, pts):
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]
data = scatter.getData()
newPos = np.vstack([data[0],data[1]]).transpose()
newLines = lines.copy()
symbolBrushs = [None] * len(data[0])
symbolBrushs[mypoint_index] = 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()
And this is the result:
来源：https://stackoverflow.com/questions/46868432/pyqtgraph-change-color-of-node-and-its-edges-on-click