def log_ncr(a, b):
    """
    Returns log(nCr(a,b)), given that b<a. Does not assume that a and b
    are integers (uses log-gamma).
    """
    val = gammaln(a+1) - gammaln(a-b+1) - gammaln(b+1)
    return val
def log_ncr ( a , b ) : val = gammaln ( a + 1 ) - gammaln ( a - b + 1 ) - gammaln ( b + 1 ) return val
Returns log(nCr(a,b)), given that b<a. Does not assume that a and b
    are integers (uses log-gamma).