Starting Crank Nicholson

Crankin

from numpy import *
from matplotlib.pyplot import *

from time import sleep

import numpy as np
import networkx as nx

dim = [2,2]

dt = .2  #time step


G = nx.generators.classic.grid_graph(dim, periodic=False, create_using=None)

L = nx.laplacian(G)

#print L.shape[0]          #gets the length of the zeroth entry of the laplacian

n = L.shape[0]

t = 100

T = 60*ones( (n,t) )		#setting initial temperature

i=0

#for i in range(t):
for i in range(t-2):
	T[:,0] = 60
	T[:,i] = 60
	
	T[:,i+2] = dot(linalg.inv( ones( (n,n) ) - dt/2*L )*(ones( (n,n) ) + dt/2*L),T[:,i+1])	#note dot(a,v) treats v as a column
																					#vector while dot(v,a) treats v like
#print T																					# a row vector

print T