libscores.py 文件源码

def tiedrank(a):
    ''' Return the ranks (with base 1) of a list resolving ties by averaging.
     This works for numpy arrays.'''    
    m=len(a)
    # Sort a in ascending order (sa=sorted vals, i=indices)
    i=a.argsort()
    sa=a[i]
    # Find unique values
    uval=np.unique(a)     
    # Test whether there are ties 
    R=np.arange(m, dtype=float)+1 # Ranks with base 1
    if len(uval)!=m:
        # Average the ranks for the ties 
        oldval=sa[0]
        newval=sa[0]
        k0=0
        for k in range(1,m):
            newval=sa[k]
            if newval==oldval:
                # moving average
                R[k0:k+1]=R[k-1]*(k-k0)/(k-k0+1)+R[k]/(k-k0+1)
            else:
                k0=k;
                oldval=newval
    # Invert the index
    S=np.empty(m)
    S[i]=R
    return S