Day 7: Spearman's Rank Correlation Coefficient.py

# Enter your code here. Read input from STDIN. Print output to STDOUT
n=input()
x=map(float,raw_input().split())
y=map(float,raw_input().split())
            
def spearmanRankCorrelationCoefficient(x,y):
        xSort=sorted(x)
        ySort=sorted(y)
        rankOfX={}
        rankOfY={}
        for i in xSort:
            rankOfX[i]= xSort.index(i)+1
        
        for i in ySort:
            rankOfY[i]= ySort.index(i)+1
        length= len(x)         
        d=[]
        for i in range(length):
           temp=rankOfX[x[i]]- rankOfY[y[i]]
           d.append(temp**2)
                 
        numerator = 6* sum(d)
        denominator = length * ((length ** 2 ) -1)         
        
        return round(1-(numerator/float(denominator)),3)
       
print spearmanRankCorrelationCoefficient(x,y)