Question

我知道这个错误通常是因为你混淆了一个函数和一个名字，一类问题。我似乎无法弄明白。

#P1

def fracSteps(N):
    """ fracSteps returns a list of N evenly spaced floating-point values starting at 0.0 and going up to, but not including 1.0
    Input: N will be a positive integer
    """

    return [ x/N   for x in range(N) ]


#P2

def steps(low,hi,N):
    """ steps returns a regularly-spaced list of N floats, starting at low and going up to, but not including, hi itself
    Input: two numbers, low and hi, and a nonnegative integer, N
    """
    return [low + (hi-low)*x for x in fracSteps(N)]
#P3

def dbl_steps(low,hi,N):
    """dbl_steps returns double each of the values in the list that of the steps function
    Input: two numbers, low and hi, and a nonnegative integer, N
    """

    return [2*x for x in steps(low,hi,N)]

#P4

def fsteps(f,low,hi,N):
    """fsteps returns the f(x) (the outpout of the function) for each of the values in the list of the steps function
    Input: function f, two numbers, low and hi, and a nonnegative integer, N
    """

    return [f(x) for x in steps(low,hi,N)]



from csplot import *

def sq(x):
    """ sq(x) squares its input
    input: x, a numeric value
    """
    return x**2

from csplot import *


#P5

def finteg(f,low,hi,N):
    """ finteg returns an estimate of the definite integral of the function f (the first input) with lower limit low (the second input) and upper limit hi (the third input) where N steps are taken (the fourth input)
    finteg simply returns the sum of the areas of rectangles under f, drawn at the left endpoint of the N steps taken from low to hi
    """


    return sum(fsteps(f,low,hi,N))*(hi-low)/(N)

def dbl(x):
    """ input: a number x (int or float)
    output: twice the input
    """
    return 2*x




#Q2

def inverse(x):


     return (1/x)



def ln(x, N):

    finteg (inverse(x),1,x,N)

    z = finteg (inverse(x),1,x,N)

    return [z]

以下是错误消息：

Traceback (most recent call last):
  File "<pyshell#0>", line 1, in <module>
    ln(42,5)
  File "C:\Users\Owner\Documents\EECS 110\Homeworks\hw2pr1.py", line 108, in ln
    finteg (inverse(x),1,x,N)
  File "C:\Users\Owner\Documents\EECS 110\Homeworks\hw2pr1.py", line 62, in finteg
    return sum(fsteps(f,low,hi,N))*(hi-low)/(N)
  File "C:\Users\Owner\Documents\EECS 110\Homeworks\hw2pr1.py", line 39, in fsteps
    return [f(x) for x in steps(low,hi,N)]
  File "C:\Users\Owner\Documents\EECS 110\Homeworks\hw2pr1.py", line 39, in <listcomp>
    return [f(x) for x in steps(low,hi,N)]
TypeError: 'float' object is not callable

Answer 1

致电时

finteg (inverse(x),1,x,N)

你正在调用函数inverse，并将返回值传递给finteg。您需要将反向传递为要评估的函数，如下所示：

finteg (inverse,1,x,N)

类型错误'float'对象不可调用

1 个答案: