Hey!, Currently I am working on a project that require a dynamic network.
So I learned about pyqtgraph and using it's examples I've made an program
in which I've implemented all the Graph functions like add edge , add node,
remove node and remove edge. And everything is working fine.
This is my code:
#!/usr/bin/env python3
from pyqtgraph.Qt import QtGui, QtCore
import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui
import numpy as np
import time
class Graph(pg.GraphItem):
def __init__(self):
self.textItems = []
pg.GraphItem.__init__(self)
self.pos = []
self.edges = []
self.texts = []
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 rescale_layout(self,pos,scale=1):
# rescale to (-scale,scale) in all axes
# shift origin to (0,0)
lim=0 # max coordinate for all axes
for i in range(pos.shape[1]):
pos[:,i]-=pos[:,i].mean()
lim=max(pos[:,i].max(),lim)
# rescale to (-scale,scale) in all directions, preserves aspect
for i in range(pos.shape[1]):
pos[:,i]*=scale/lim
return pos
def getNodePosn(self,n):
if n==1:
return [[0,0]]
theta = np.linspace(0, 1, n + 1)[:-1] * 2 * np.pi
theta = theta.astype(np.float32)
pos = np.column_stack([np.cos(theta), np.sin(theta)])
pos = self.rescale_layout(pos, scale=1)+(0,0)
return pos
def add_node(self,name):
if name not in self.texts:
n = len(self.pos)
self.pos = self.getNodePosn(n+1)
print(self.pos)
self.texts.append(name)
self.setData(pos=np.array(self.pos,dtype=float),
adj=np.array(self.edges,dtype=int),size=0.1, pxMode=False,
text=np.array(self.texts))
print(name + " added ")
def remove_node(self,n):
# pass
self.pos = np.delete(self.pos,n,axis=0)
self.texts = np.delete(self.texts,n,axis=0)
print(self.pos.shape)
for edge in self.edges:
if edge[0]==n or edge[1]==n:
self.remove_edge(edge)
self.setData(pos=np.array(self.pos,dtype=float),
adj=np.array(self.edges,dtype=int),size=0.1, pxMode=False,
text=np.array(self.texts))
self.setData(pos=np.array(self.pos,dtype=float),
adj=np.array(self.edges,dtype=int),size=0.1, pxMode=False,
text=np.array(self.texts))
print(str(n) + " node removed ")
def add_edge(self,edge):
if edge not in self.edges:
print("%s Edge Added"%edge)
self.edges.append(edge)
self.setData(pos=np.array(self.pos,dtype=float),
adj=np.array(self.edges,dtype=int),size=0.1, pxMode=False,
text=np.array(self.texts))
print(self.edges)
def remove_edge(self,edge):
print(self.edges)
if edge in self.edges:
self.edges.remove(edge)
self.setData(pos=np.array(self.pos,dtype=float),
adj=np.array(self.edges,dtype=int),size=0.1, pxMode=False,
text=np.array(self.texts))
self.updateGraph()
print("%s Edge removed"%edge)
else:
print("No such edge exist")
## Start Qt event loop unless running in interactive mode or using pyside.
if __name__ == '__main__':
import sys,time
# Enable antialiasing for prettier plots
app = QtGui.QApplication([])
pg.setConfigOptions(antialias=True)
w = pg.GraphicsWindow()
w.setWindowTitle('pyqtgraph example: CustomGraphItem')
w.resize(800,600)
v = w.addViewBox()
v.setAspectLocked()
## Define positions of nodes
g = Graph()
v.addItem(g)
g.add_node('node 0')
g.add_node('node 1')
g.add_node('node 2')
g.add_node('node 3')
g.add_node('node 4')
add_edges = [[0,1],[1,2],[0,2],[3,4],[1,4]]
for edge in add_edges:
g.add_edge(edge)
app.processEvents()
time.sleep(1)
remove_edges = [[0,2],[1,2],[3,4],[0,1],[1,4]]
for edge in remove_edges:
g.remove_edge(edge)
app.processEvents()
time.sleep(1)
But I'm facing some issue with remove edge functionality. I able to remove
all edges except the last one. And it throws following error.
File
"/Users/sachinsingh/Desktop/Desktop/Development/projects/p2psp/PyQtExperiments/venv/lib/python3.6/site-packages/pyqtgraph/graphicsItems/GraphItem.py",
line 131, in paint
self.generatePicture()
File
"/Users/sachinsingh/Desktop/Desktop/Development/projects/p2psp/PyQtExperiments/venv/lib/python3.6/site-packages/pyqtgraph/graphicsItems/GraphItem.py",
line 123, in generatePicture
pts = pts.reshape((pts.shape[0]*pts.shape[1], pts.shape[2]))
IndexError: tuple index out of range
Abort trap: 6
I think this due to the fact that when I remove all of the edges the list
become empty and so as the points. Hence have no shape.
Please help me out !
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