from __future__ import division
import networkx as nx
import matplotlib.pyplot as plt
import numpy as np
from numpy.linalg import inv

G = nx.Graph()

pos={1:(2,3),2:(0,0),3:(6,0)}
G.add_nodes_from(pos.keys())
nx.set_node_attributes(G, 'coord', pos)

PE={1:0,2:60,3:40}
nx.set_node_attributes(G,'PE',PE)
q={1:100,2:0,3:0}
nx.set_node_attributes(G,'q',q)

G.add_edge(1,2)
G.add_edge(1,3)
G.add_edge(2,3)

import math
lengths={}
inv_lengths={}
for edge in G.edges():
    startnode=edge[0]
    endnode=edge[1]
    lengths[edge]=round(math.sqrt(((pos[endnode][1]-pos[startnode][1])**2)+
                                      ((pos[endnode][0]-pos[startnode][0])**2)),2)
    inv_lengths[edge]=round(1/lengths[edge],3)
nx.set_edge_attributes(G, 'length', lengths)
nx.set_edge_attributes(G, 'inv_length', inv_lengths)
nx.draw(G,pos,node_size=1000,node_color='r',with_labels=True)
nx.draw_networkx_edge_labels(G,pos,edge_labels=flow)
plt.show()

b=[]
for i,v in enumerate(PE.values()):
    b.append(v)
res2=np.dot(a,b) #No inverse is required: x=ab
res2=[round(item,3) for sublist in res2.tolist() for item in sublist]
print res2

#res=[-24.62, 19.96, 4.66]