二项分布B（0.75,1000）的概率曲线（经过调整）
基于pygame。
坐标轴单位长度尚未标记。
代码如下：
import pygame, sys
import math
def combination(part,total):
numerator = math.factorial(total)
difference = total - part
denominator = math.factorial(difference) * math.factorial(part)
result = numerator/denominator
return result
pygame.init()
screen = pygame.display.set_mode([640,480])
screen.fill([255,255,255])
plotPoints = []
xaxis = [[0,240],[640,240]]
yaxis = [[320,0],[320,480]]
pygame.draw.lines(screen,[0,0,0],False,xaxis,1)
pygame.draw.lines(screen,[0,0,0],False,yaxis,1)
for x in range(1,1000):
front = combination(x,1000)
y = -(front * 0.75**(x)*0.25**(1000-x)*5000)+240
plotPoints.append([(x-430)*3-640,y])
pygame.draw.lines(screen,[0,0,0],False,plotPoints,1)
pygame.display.flip()
running = True
while running :
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
pygame.quit()
运行效果如下：
