问题描述
我正在使用scipy.optimize.minimize
,并且正在使用这样的函数优化3个参数
I'm working with scipy.optimize.minimize
, and I'm optimizing 3 parameters with a function like this
def foo(A, x, y, z):
test = my_function(A[0], A[1], A[2], x, y, z)
return test
在这个答案中,我发现了一些见识:如何显示scipy.optimize函数的进度?所以我想出了这个功能:
In this answer I found some insight:How to display progress of scipy.optimize function?So I came up with this function:
def callbackF(Xi, x, y, z)
global Nfeval
print '{0:4d} {1: 3.6f} {2: 3.6f} {3: 3.6f} {4: 3.6f}'.format(Nfeval, Xi[0], Xi[1], Xi[2], foo(Xi, x, y, z))
Nfeval += 1
所以我的代码看起来像这样
So my code will look like this
Optimal = minimize(fun=foo, x0=[fi, alfa, Ks], args=(x, y, z),
method='BFGS', callback=callbackF, tol=1e-2)
但是我得到这个错误:
TypeError: callbackF() takes exactly 4 arguments (1 given)
我了解该错误,但是应该如何避免呢?
I understand the error, but how should I avoid it?
推荐答案
如果您可以自己检测函数本身,则可以随时对其进行DIY.唯一棘手的问题是迭代计数.为此,您既可以使用全局函数,也可以使用(更好的是IMO)将计数器附加到函数本身:
You can always DIY it if you can instrument the function itself. The only tricky bit is the iteration count. For it you can either use a global, or (IMO, better) attach the counter to the function itself:
>>> import numpy as np
>>> from scipy.optimize import minimize
>>>
>>> def f(x):
... res = np.sum(x**2)
... f.count += 1
... print('x = ', x, ' res = ', res, ' j = ', f.count)
... return res
...
>>> f.count = 0
>>> minimize(f, x0=5)
x = [ 5.] res = 25.0 j = 1
x = [ 5.00000001] res = 25.000000149 j = 2
x = [ 5.] res = 25.0 j = 3
x = [-5.] res = 25.0 j = 4
x = [-5.] res = 25.0 j = 5
x = [-4.99999999] res = 24.999999851 j = 6
x = [ 0.0005] res = 2.5e-07 j = 7
x = [ 0.0005] res = 2.5e-07 j = 8
x = [ 0.00050001] res = 2.50014901383e-07 j = 9
x = [ -7.45132485e-09] res = 5.55222420558e-17 j = 10
x = [ -7.45132485e-09] res = 5.55222420558e-17 j = 11
x = [ 7.44983634e-09] res = 5.55000615146e-17 j = 12
fun: 5.552224205575604e-17
hess_inv: array([[ 0.5]])
jac: array([ -1.48851092e-12])
message: 'Optimization terminated successfully.'
nfev: 12
nit: 2
njev: 4
status: 0
success: True
x: array([ -7.45132485e-09])
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