Feature SIR function

functions.py

@@ -1,4 +1,26 @@
 #!/usr/bin/python
+def islandPerimeter(grid):
+    """
+    The solution to today's leetcode challenge.
+    :type grid: List[List[int]]
+    :rtype: int
+    """
+
+    leni = len(grid)
+    lenj = len(grid[0])
+
+    def countCell(i,j):
+        if not grid[i][j]:
+            return 0
+        borders = 4
+        if i>0 and grid[i-1][j]: borders -= 1
+        if i<(leni-1) and grid[i+1][j]: borders -= 1
+        if j<(lenj-1) and grid[i][j+1]: borders -= 1
+        if j>0 and grid[i][j-1]: borders -= 1
+        return borders
+
+    return sum([countCell(i,j) for i in range(leni) for j in range(lenj)])
+
 
 """This program uses scipy to integrate and plot the results of a basic SIR model"""
 
@@ -8,7 +30,7 @@
 from pylab import *
 
 #Define Constants
-Beta=2.0
+beta=2.0
 gamma=.8
 init=array([0.95,0.05,0.0])
 finalTime=20.0
@@ -18,8 +40,8 @@ def derv(x,t):
     """Computes the derv operator for the basic sir model"""
 
     y=zeros(3); 
-    y[0]=-Beta*x[0]*x[1]
-    y[1]=Beta*x[0]*x[1]-gamma*x[1]
+    y[0]=-beta*x[0]*x[1]
+    y[1]=beta*x[0]*x[1]-gamma*x[1]
     y[2]=gamma*x[1]
     return(y)