代码更正

Question

我一直在尝试为这个函数编写代码，但我不能让asin在python 2.7中工作。任何想法为什么？

import math
from decimal import *

def main():
    H = raw_input ("Please enter hight:")
    H = int(float(H))
    m = raw_input ("Please enter crest thickness:")
    m = int(float(m))
    n = raw_input ("Please enter base thikness:")
    n = int(float(n))

    Fx = 0.0
    Fy = 0.0
    Magnitude = 0.0
    Direction = 0.0

p = 1000 #dencity
g = 9.81 #gravity

R = math.sqrt(H*H + n*n)
#Force in x direction
Fx = (-p*g*m*(H*H))/2.0
#Force in y direction
Fy = -p*g*R*(((math.asin(n/H))/2.0)-sin((2*math.asin(n/H))/4.0))

#Overall force
Direction = math.atan(Fy/Fx)
Magnitude = sqrt(Fx*Fy + Fy*Fy)

print ("The force magnitude is", Magnitude)
print ("The force direction is", Direction)

Answer 1

将整数除以整数（与n/H中的math.asin(n/H)一样）会在3.0之前的Python中返回一个整数（这是除法结果的最低值）。您必须将至少一个操作数转换为float或在Python源文件的开头声明

from __future__ import division

阅读http://python.org/dev/peps/pep-0238了解详情

Answer 2

代码更正

有一些问题：

没有内置<a>，需要在math中使用math.sin
```
sin
```
有zero division。
```
---> 23 Fy = -p*g*R*(((math.asin(n/H))/2.0)-sin((2*math.asin(n/H))/4.0))

NameError: name 'sin' is not defined
```
这来自---> 26 Direction = math.atan(Fy/Fx) ZeroDivisionError: float division by zero整数除以@MichaelButscher states。
内置n/H，也使用math.sqrt
```
sqrt
```
如果输入为---> 30 Magnitude = sqrt(Fx*Fy + Fy*Fy) NameError: name 'sqrt' is not defined，则会将其截断为float，这似乎没必要。

最终更正的代码：

int

import math
from decimal import *
from __future__ import division

H = 10.0 # raw_input("Please enter hight:")
H = float(H)
m = 0.2 # raw_input("Please enter crest thickness:")
m = float(m)
n = 2.0 # raw_input("Please enter base thikness:")
n = float(n)

Fx = 0.0
Fy = 0.0
Magnitude = 0.0
Direction = 0.0

p = 1000 #dencity
g = 9.81 #gravity

R = math.sqrt(H*H + n*n)
#Force in x direction
Fx = (-p*g*m*(H*H))/2.0
#Force in y direction
Fy = -p*g*R*(((math.asin(n/H))/2.0)-math.sin((2*math.asin(n/H))/4.0))

#Overall force
Direction = math.atan(Fy/Fx)
Magnitude = math.sqrt(Fx*Fy + Fy*Fy)

print ("The force magnitude is", Magnitude)
print ("The force direction is", Direction)

asin函数在python中不起作用

2 个答案:

代码更正