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Plot the network of the first 1000 #cn220 tweets with igraph and cairo.
'''
@author Michael J Bommarito II
@contact michael.bommarito@gmail.com
@date Feb 21, 2011
@license Simplified BSD, (C) 2011.
Plot the network of the first 1000 #cn220 tweets with igraph and cairo.
'''
import cairo
import codecs
import dateutil.parser
import igraph
import numpy
import re
def readTweets(fileName):
'''
Read in tweet data from the tab-delimited tweet format.
'''
rows = [[field.strip() for field in line.split("\t")] for line in codecs.open(fileName, 'r', 'utf-8')]
return [(int(row[0]), dateutil.parser.parse(row[1]), row[2], row[3]) for row in rows]
def getNetwork(tweets):
'''
Parse the list of tweets and find "edges" embedded in the tweets.
Edges are just mentions in the tweet text, e.g., @mjbommar.
Then process the network from the edges.
'''
reMention = re.compile('\@([\w]+)')
# Calculate the list of mentions
mentions = []
for tweet in tweets:
mentions.extend([(tweet[1], tweet[2], name) for name in reMention.findall(tweet[3])])
# Sort by date
mentions = sorted(mentions)
# Now convert the dates/mention to edges and weights
dates, nodeA, nodeB = zip(*mentions)
nodes = set(nodeA) | set(nodeB)
nodes = sorted(list(nodes))
nodeMap = dict([(v,i) for i,v in enumerate(nodes)])
edges = [(nodeMap[e[1]], nodeMap[e[2]]) for e in mentions]
edges, weights = map(list, zip(*[[e, edges.count(e)] for e in set(edges)]))
# Now create the graph
graph = igraph.Graph(edges)
graph.es['weight'] = weights
graph.vs['label'] = nodes
return graph
def project2D(layout, alpha, beta):
'''
This method will project a set of points in 3D to 2D based on the given
angles alpha and beta.
'''
# Calculate the rotation matrices based on the given angles.
c = numpy.matrix([[1, 0, 0], [0, numpy.cos(alpha), numpy.sin(alpha)], [0, -numpy.sin(alpha), numpy.cos(alpha)]])
c = c * numpy.matrix([[numpy.cos(beta), 0, -numpy.sin(beta)], [0, 1, 0], [numpy.sin(beta), 0, numpy.cos(beta)]])
b = numpy.matrix([[1, 0, 0], [0, 1, 0], [0, 0, 1]])
# Hit the layout, rotate, and kill a dimension
layout = numpy.matrix(layout)
X = (b * (c * layout.transpose())).transpose()
return [[X[i,0],X[i,1],X[i,2]] for i in range(X.shape[0])]
def drawGraph3D(graph, layout, angle, fileName):
'''
Draw a graph in 3D with the given layout, angle, and filename.
'''
# Setup some vertex attributes and calculate the projection
graph.vs['degree'] = graph.degree()
vertexRadius = 0.1 * (0.9 * 0.9) / numpy.sqrt(graph.vcount())
graph.vs['x3'], graph.vs['y3'], graph.vs['z3'] = zip(*layout)
layout2D = project2D(layout, angle[0], angle[1])
graph.vs['x2'], graph.vs['y2'], graph.vs['z2'] = zip(*layout2D)
minX, maxX = min(graph.vs['x2']), max(graph.vs['x2'])
minY, maxY = min(graph.vs['y2']), max(graph.vs['y2'])
minZ, maxZ = min(graph.vs['z2']), max(graph.vs['z2'])
# Calculate the draw order. This is important if we want this to look
# realistically 3D.
zVal, zOrder = zip(*sorted(zip(graph.vs['z3'], range(graph.vcount()))))
# Setup the cairo surface
surf = cairo.ImageSurface(cairo.FORMAT_ARGB32, 1280, 800)
con = cairo.Context(surf)
con.scale(1280.0, 800.0)
# Draw the background
con.set_source_rgba(0.0, 0.0, 0.0, 1.0)
con.rectangle(0.0, 0.0, 1.0, 1.0)
con.fill()
# Draw the edges without respect to z-order but set their alpha along
# a linear gradient to represent depth.
for e in graph.get_edgelist():
# Get the first vertex info
v0 = graph.vs[e[0]]
x0 = (v0['x2'] - minX) / (maxX - minX)
y0 = (v0['y2'] - minY) / (maxY - minY)
alpha0 = (v0['z2'] - minZ) / (maxZ - minZ)
alpha0 = max(0.1, alpha0)
# Get the second vertex info
v1 = graph.vs[e[1]]
x1 = (v1['x2'] - minX) / (maxX - minX)
y1 = (v1['y2'] - minY) / (maxY - minY)
alpha1 = (v1['z2'] - minZ) / (maxZ - minZ)
alpha1 = max(0.1, alpha1)
# Setup the pattern info
pat = cairo.LinearGradient(x0, y0, x1, y1)
pat.add_color_stop_rgba(0, 1, 1.0, 1.0, alpha0 / 6.0)
pat.add_color_stop_rgba(1, 1, 1.0, 1.0, alpha1 / 6.0)
con.set_source(pat)
# Draw the line
con.set_line_width(vertexRadius / 4.0)
con.move_to(x0, y0)
con.line_to(x1, y1)
con.stroke()
# Draw vertices in z-order
for i in zOrder:
v = graph.vs[i]
alpha = (v['z2'] - minZ) / (maxZ - minZ)
alpha = max(0.1, alpha)
radius = vertexRadius
x = (v['x2'] - minX) / (maxX - minX)
y = (v['y2'] - minY) / (maxY - minY)
# Setup the radial pattern for 3D lighting effect
pat = cairo.RadialGradient(x, y, radius / 4.0, x, y, radius)
pat.add_color_stop_rgba(0, alpha, 0, 0, 1)
pat.add_color_stop_rgba(1, 0, 0, 0, 1)
con.set_source(pat)
# Draw the vertex sphere
con.move_to(x, y)
con.arc(x, y, radius, 0, 2 * numpy.pi)
con.fill()
# Output the surface
surf.write_to_png(fileName)
if __name__ == "__main__":
# Load the tweets
tweets = readTweets("data/tweets_cn220.csv")
# Determine how many tweets we'll use to construct the network.
numTweets = 1000
# Load the graph, isolate the giant component, and calculate the layout.
graph = getNetwork(tweets[0:numTweets])
graph = graph.components(mode=igraph.WEAK).giant()
layout = graph.layout_kamada_kawai_3d()
# Now draw the frames while rotating.
for frame in range(400):
alpha = frame * numpy.pi / 200.
beta = frame * numpy.pi / 150.
print frame, alpha, beta
drawGraph3D(graph, layout, (alpha, beta), "frames/%08d.png" % (frame))
@Uiuran

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commented Mar 25, 2013

Hi, i merged this code with a previous forked animation code, hope you dont get troubled by this. Many thanks again.

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