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python - 创建一个程序，用笛卡尔坐标和极坐标计算矢量结果

问题描述

我需要创建一个计算矢量结果的程序，但我需要允许用户在极坐标和笛卡尔坐标之间进行选择。这是我到目前为止所拥有的，但它给了我错误，我不确定如何询问用户 x,y 坐标以及如何在输入向量后让程序停止。请帮忙，我对这个了解不多！

导入数学 #calculate 向量分量并从极坐标变为笛卡尔坐标，反之亦然


def fxcomponent(x, y):              # to find cartesian x
  number = x
  y = math.cos(math.degrees(y))
  result = number * y
  return result

def fycomponent(x, angle):          #to find cartesian y
  number = x 
  angle = math.sin(math.degrees(angle))
  result = number * angle
  return result

def polar_length(r,t):              #to find polar lenght
    number = r
    length =((r**2) + (t**2))
    result = math.sqrt(number)
    return result
    
def polar_angle(r,theta):           #to find polar angle
    result = math.atan2(theta,r)
    return result


#prompts
prompt = 'Hi!'
type_coor = input('Enter the type of coordinate you will use: use p for polar \n enter c for cartesian')
vector_number = input('Enter the number of vectors you will be adding: ')
i = 0
while i <= vector_number:
    if type_coor == 'p':                     #if polar values are entered
        print('What is the r value?:')
        x, angle = [int(x) for x in input('>').split()]
        result = fxcomponent(x, angle)
        print('The x component of %d at %d° is: %d' % (x, angle, result))
    elif type_coor == 'p':
        print ('What is the value of the angle?:')
        y, angle = [int(x) for x in input('>').split()]
        result = fycomponent(y, angle)
        print('The y component of %d at %d° is: %d' % (y, angle, result))```

标签： pythonvector

解决方案

这里有很多不同的错误来源，这是一项艰巨的任务......

首先，如果有人输入了意想不到的东西，这段代码就会中断，

要解决此问题，您可以使用 if 条件来检查输入值是否正常，如下所示：

variable = input('enter "c" or "p" \n>>')
if variable not in ['c','p']: # to check if variable is in the list
    exit() # quit the program 

# and for a number (integer only !!!)
variable = input('enter a number \n>>')
if !variable.isnumeric():
    exit()

那么，我对您在这里使用的数学了解不多，但是，如果您在顶部的 4 个函数是正确的，那么您应该要求每个变量具有不同的输入，并使用您的if ... elifonly 来区分type_coord == 'p'和type_coord == 'c'

像这样的东西有效，但它只适用于整数，我相信这不是你想要的：

#prompts
prompt = 'Hi!'

type_coor = input('Enter the type of coordinate you will use: \nuse p for polar \nenter c for cartesian \n("q" for quit):\n>> ')
if type_coor not in ['c', 'p']:
    print('coordinate type must be "c" or "p"')
    exit() # quitting the program

vector_number = input('Enter the number of vectors you will be adding: \n>> ')
if vector_number.isnumeric() == False:
    print('must be integer')
    exit()
vector_number = int(vector_number)

i = 0
while i < vector_number:
    if type_coor == 'p':                     #if polar values are entered
        r = input('What is the r value?: \n>>')
        if r.isnumeric() == False:
            print('r must be integer')
            exit()
        r = int(r)

        t = input('What is the t value?: \n>>')
        if t.isnumeric() == False:
            print('theta must be integer')
            exit()
        t = int(t)

        theta = input('What is the theta value?: \n>>')
        if theta.isnumeric() == False:
            print('theta must be integer')
            exit()
        theta = int(theta)
        
        length = polar_length(r, t)
        angle = polar_angle(r,theta)
        print('length = %d' % (length))
        print('angle = %d' % (angle))
    
    elif type_coor == 'c':              # if cartesian values are entered
        # do the same for cartesian coordinates
    i += 1

如果您想使用十进制值，那么代码会变得更加复杂。对于每个浮点值，您应该执行以下操作：

variable = input('enter a decimal \n>> ')
try:
    variable = float(variable)
except ValueError:
    print('not a decimal')
    exit()

...最后一步是用循环替换所有if输入条件检查，这些while循环要求用户输入一个值，直到该值正确为止...

希望这会有所帮助，玩得开心！

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