'numpy.ndarray' object is not callable 错误 optimize.minimize

'numpy.ndarray' object is not callable error with optimize.minimize

我想用一个简单的 sin^2 函数拟合一组数据,并根据拟合参数确定它的最小值。

这是我的代码:

import numpy as np
import matplotlib.pyplot as plt
from scipy import optimize

data = np.loadtxt('data.txt', usecols=(0,1))
x = data[:,0]*np.pi/180
y = data[:,1]

plt.scatter(x, y, c='red')

def sine(t,a,b,c):
    return a*(np.sin(b*(t-c)))**2

params, cov = optimize.curve_fit(sine, x, y, p0=[9500, 0.5, 0])
print(params)

t = np.linspace(0, 2*np.pi/3, 120) 
plt.plot(t, sine(t, *params), 'black')

plt.show()

optimize.minimize(sine(t, *params), x0=0)

除了 minimize 调用外一切正常,因为我收到以下错误(带有完整的回溯):

TypeError                                 Traceback (most recent call last)
~\Documents\CNR\Calibrazione_lamine_20181112\Fit.py in <module>()
     23 plt.show()
     24 
---> 25 optimize.minimize(sine(t, *params), x0=0)

~\Anaconda3\lib\site-packages\scipy\optimize\_minimize.py in minimize(fun, x0, args, method, jac, hess, hessp, bounds, constraints, tol, callback, options)
    442         return _minimize_cg(fun, x0, args, jac, callback, **options)
    443     elif meth == 'bfgs':
--> 444         return _minimize_bfgs(fun, x0, args, jac, callback, **options)
    445     elif meth == 'newton-cg':
    446         return _minimize_newtoncg(fun, x0, args, jac, hess, hessp, callback,

~\Anaconda3\lib\site-packages\scipy\optimize\optimize.py in _minimize_bfgs(fun, x0, args, jac, callback, gtol, norm, eps, maxiter, disp, return_all, **unknown_options)
    911     else:
    912         grad_calls, myfprime = wrap_function(fprime, args)
--> 913     gfk = myfprime(x0)
    914     k = 0
    915     N = len(x0)

~\Anaconda3\lib\site-packages\scipy\optimize\optimize.py in function_wrapper(*wrapper_args)
    290     def function_wrapper(*wrapper_args):
    291         ncalls[0] += 1
--> 292         return function(*(wrapper_args + args))
    293 
    294     return ncalls, function_wrapper

~\Anaconda3\lib\site-packages\scipy\optimize\optimize.py in approx_fprime(xk, f, epsilon, *args)
    686 
    687     """
--> 688     return _approx_fprime_helper(xk, f, epsilon, args=args)
    689 
    690 

~\Anaconda3\lib\site-packages\scipy\optimize\optimize.py in _approx_fprime_helper(xk, f, epsilon, args, f0)
    620     """
    621     if f0 is None:
--> 622         f0 = f(*((xk,) + args))
    623     grad = numpy.zeros((len(xk),), float)
    624     ei = numpy.zeros((len(xk),), float)

~\Anaconda3\lib\site-packages\scipy\optimize\optimize.py in function_wrapper(*wrapper_args)
    290     def function_wrapper(*wrapper_args):
    291         ncalls[0] += 1
--> 292         return function(*(wrapper_args + args))
    293 
    294     return ncalls, function_wrapper

TypeError: 'numpy.ndarray' object is not callable.

我遗漏了一些东西,但我不知道是什么。


我正在按照建议添加数据文件来制作此程序运行

0   405
5   20
10  350
15  1380
20  2900
25  4750
30  6450
35  8100
40  9100
45  9800
50  10100
55  10250
60  9400
65  8400
70  6430
75  4900
80  3030
85  1500
90  400
95  17
100 410
105 1550
110 3100
115 4850
120 6780

在 scipy 的文档中,optimize.minimize 函数将 ndarrayshape(n) 作为 x, 的输入,而不是整数。我认为错误是从那里引发的,因为在他们的错误跟踪中

--> 913     gfk = myfprime(x0)

此函数引发错误。

文档 link.

minimize 需要一个函数作为第一个参数,但是,您目前传递

sine(t, *params)

这是一个 numpy 数组。

您可以解决此问题并执行以下操作:

print(optimize.minimize(sine, x0=[0], args=tuple(params)))

这将打印

      fun: 2.4080485986582715e-12
 hess_inv: array([[1.15258817e-05]])
      jac: array([8.19961349e-09])
  message: 'Optimization terminated successfully.'
     nfev: 18
      nit: 4
     njev: 6
   status: 0
  success: True
        x: array([0.09203053])