Python 计算置信区间

Python 计算置信区间

用Python实现http://vassarstats.net/prop1.html 所计算的置信区间

import math
#计算置信区间的函数
def calc(r,n):
	if n < r :
		print ('r cannot be greater than n.')
		return 
	if math.floor(r) < r :
		print ('r must be an integer value.')
		return 
	if math.floor(n) < n :
		print ('n must be an integer value.')
		return
	p = round((r/n)*10000)/10000
	print ('p',p)

	q = 1-p
	p = round(p*10000)/10000
	print ('p',p)
	z=1.95996
	zsq = z*z
	
	# l95a
	num = (2*n*p)+zsq-(z*math.sqrt(zsq+(4*n*p*q)))
	denom = 2*(n+zsq)
	l95a = num/denom
	if p == 0 :
		l95a = 0
	l95a = round(l95a*10000)/10000
	
	# u95a
	num = (2*n*p)+zsq+(z*math.sqrt(zsq+(4*n*p*q)))
	denom = 2*(n+zsq)
	u95a = num/denom
	print ('u95a',u95a)
	if p == 1 :
		u95a = 1
	u95a = round(u95a*10000)/10000
	print('no continuity correction',l95a,'-',u95a)
	
	
	
	# l95b
	num = (2*n*p)+zsq-1-(z*math.sqrt(zsq-2-(1/n)+4*p*((n*q)+1)))
	denom = 2*(n+zsq)
	l95b = num/denom
	if p==0 :
		l95b = 0
	l95b = round(l95b*100000000)/100000000
	
	# u95b
	num = (2*n*p)+zsq+1+(z*math.sqrt(zsq+2-(1/n)+4*p*((n*q)-1)))
	denom = 2*(n+zsq)
	u95b = num/denom
	if p==1 :
		u95b = 1
	u95b = round(u95b*100000000)/100000000
	print('including continuity correction',l95b,'-',u95b)
	
	
	return
	


#测试k = 12 n = 40

calc(12,40)
print('THE END')