python 练习题

　　python是一个功能很强大的语言，他可以解决各种在数学问题，下面我分享一些练习题供大家参考：

有关正态分布的问题：

# -*- coding: cp936 -*-
import math
a=0
u=0
x=0
while 1:
    a =int(input("please input a :"))
    ifa<0:
       print "请重新输入："
    elifa>0:
       break;
u = int(input("please intput u :"))
x = int(input("please intput x :"))
fs =(1/math.sqrt(2*math.pi)*a)*math.exp(0.5*(math.pow(((x-u)/a),2)))
print "this fs is :%.2f"%fs;

关于平抛运动矢量位移：

v0 =10
g= 9.81
#t = int(input("please input a time:"))
#h = v0*t+0.5*g*t**2
#print "this h is :%.2f"%h;

while 1:
    h =int(input("please input a hight:"))
    #h =v0*t+0.5*g*t**2
    t1=(-v0+(v0**2-4*0.5*g*(-h))**0.5)/(2*0.5*g)
    t2=(-v0-(v0**2-4*0.5*g*(-h))**0.5)/(2*0.5*g)
    ift1>0:
       print "this time1 is:%.2f"%t1;   
    ift2>0:
       print "this time2 is :%.2f"%t2;

python的函数式编程

　　判断一个数是不是质数：

 >>>f = lambda x:not reduce(lambda x,y:x or y,[x%i==0 for i inrange(2,x)])
>>> f(97)
True
>>> f(96)
False  

　　求最大公约数：

>>> f = lambdam,n:[i for i in range(min(m,n),0,-1) if m%i==0 and n%i==0][0]
>>> f(123,77)
1
>>> f(125,100)
25

计算给定数字的阶乘：

>>> f = lambdax:reduce(lambda x,y:x*y,[i for i in range(1,x+1)])
>>> f(5)
120

>>> zip3 = lambdal1,l2,l3:[(l1[i],l2[i],l3[i]) for i in range(len(l1))]
>>>zip3([1,2,3],['a','b','c'],[1j,2j,3j])
[(1, 'a', 1j), (2, 'b', 2j), (3, 'c', 3j)]

python的reduce函数的应用：

>>> f = lambdal:reduce(lambda x,y:x*y,l)
>>> f(l)
0
>>>f([1,2,2,3,4])
48

蒙特卡洛近似求解

　　1.求圆周率：

import random
import math
def round_(num):
    i=0
   number=0.0
    whilei<num:
       x = random.random()
       y = random.random()
      
       y_=s(x)
       if y<=y_:
           number+=1
       i+=1
    return4*number/num
def s(a):
    returnmath.sqrt(1-math.pow(a,2))

　　2.求面积：

import random
def f(num):
    i=0
    s=0.0
    while i<num:
        x = random.random()
        #print x
        y = random.random()
        y_=ft(x)
        if y<=y_:
            s+=1
        i+=1
    return s/num
  
   
def ft(a) :
    return a*a