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저는 아직 파이썬에서 초보자입니다. 너무 사소한 경우 미안합니다. 총 12 개의 변수가있는 함수의 최소값을 계산하고 싶습니다. 이 12 개의 변수 중 10 개가 주어진 값에 고정되어 있고 나머지 2 개는 최소값을 계산할 자유입니다. 다음은 내 코드 예제입니다. 코드 조각에 따라무료 및 고정 매개 변수가있는 sympy의 최소화 함수 ('SLSQP'메서드) 사용
은import numpy as np
from sympy import *
from scipy.optimize import minimize
init_printing(use_unicode=True)
X_1,X_2,Y_1,Y_2,X_c1,X_c2,Y_c1,Y_c2,a_1,a_2,b_1,b_2,t_1,t_2,psi_1,psi_2= symbols('X_1 X_2 Y_1 Y_2 X_c1 X_c2 Y_c1 Y_c2 a_1 a_2 b_1 b_2 t_1 t_2 psi_1 psi_2')
X_1=X_c1 + (a_1 * cos(t_1) * cos(psi_1)) - ((b_1) * sin(t_1)* sin(psi_1))
X_2=X_c2 + (a_2 * cos(t_2) * cos(psi_2)) - ((b_2) * sin(t_2)* sin(psi_2))
Y_1=Y_c1 + (a_1 * cos(t_1) * sin(psi_1)) + ((b_1) * sin(t_1)* cos(psi_1))
Y_2=Y_c2 + (a_2 * cos(t_2) * sin(psi_2)) + ((b_2) * sin(t_2)* sin(psi_2))
param=(t_1,t_2,X_c1,X_c2,Y_c1,Y_c2,a_1,a_2,b_1,b_2,psi_1,psi_2) #12 parameters, 10 are fixed and 2 are free.
free_param=(t_1,t_2) #These are my two free parameters
D=((X_2-X_1)**2 + (Y_2-Y_1)**2)**0.5 #Expression to be minimised
distance=lambdify(param, D, modules='numpy')
이 링크를 기반으로하고있다 : Want to do multi-variation minimize with sympy
#Build Jacobian:
jac_D=[D.diff(x) for x in param]
jac_distance=[lambdify(param, jf, modules='numpy') for jf in jac_D]
def vector_distance(zz):
""" Helper for receiving vector parameters """
return distance(zz[0], zz[1], zz[2], zz[3], zz[4], zz[5], zz[6], zz[7], zz[8], zz[9], zz[10], zz[11])
def jac_vector_distance(zz):
""" Jacobian Helper for receiving vector parameters """
return np.array([jfn(zz[0], zz[1], zz[2], zz[3], zz[4], zz[5], zz[6], zz[7], zz[8], zz[9], zz[10], zz[11]) for jfn in jac_distance])
zz0 = np.array([np.pi/2, np.p1/2]) #Guess values for t_1 and t_2
가 지금은 다른 10 개 변수의 값을 수정합니다. 나는 제약을 사용하는 것을 생각했다.
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
TypeError: can't convert expression to float
During handling of the above exception, another exception occurred:
SystemError Traceback (most recent call last)
SystemError: <built-in function hasattr> returned a result with an error set
During handling of the above exception, another exception occurred:
SystemError Traceback (most recent call last)
SystemError: <built-in function hasattr> returned a result with an error set
During handling of the above exception, another exception occurred:
SystemError Traceback (most recent call last)
SystemError: <built-in function hasattr> returned a result with an error set
During handling of the above exception, another exception occurred:
SystemError Traceback (most recent call last)
SystemError: <built-in function hasattr> returned a result with an error set
During handling of the above exception, another exception occurred:
SystemError Traceback (most recent call last)
SystemError: <built-in function hasattr> returned a result with an error set
During handling of the above exception, another exception occurred:
SystemError Traceback (most recent call last)
SystemError: <built-in function hasattr> returned a result with an error set
During handling of the above exception, another exception occurred:
SystemError Traceback (most recent call last)
SystemError: <built-in function hasattr> returned a result with an error set
During handling of the above exception, another exception occurred:
SystemError Traceback (most recent call last)
SystemError: <built-in function hasattr> returned a result with an error set
During handling of the above exception, another exception occurred:
SystemError Traceback (most recent call last)
<ipython-input-18-fc64da7d0cae> in <module>()
----> 1 rslts = minimize(vector_distance, zz0, method='SLSQP', jac=jac_vector_distance, constraints=cons)
/users/vishnu/anaconda3/lib/python3.5/site-packages/scipy/optimize/_minimize.py in minimize(fun, x0, args, method, jac, hess, hessp, bounds, constraints, tol, callback, options)
453 elif meth == 'slsqp':
454 return _minimize_slsqp(fun, x0, args, jac, bounds,
--> 455 constraints, callback=callback, **options)
456 elif meth == 'dogleg':
457 return _minimize_dogleg(fun, x0, args, jac, hess,
/users/vishnu/anaconda3/lib/python3.5/site-packages/scipy/optimize/slsqp.py in _minimize_slsqp(func, x0, args, jac, bounds, constraints, maxiter, ftol, iprint, disp, eps, callback, **unknown_options)
404
405 # Call SLSQP
--> 406 slsqp(m, meq, x, xl, xu, fx, c, g, a, acc, majiter, mode, w, jw)
407
408 # call callback if major iteration has incremented
/users/vishnu/anaconda3/lib/python3.5/site-packages/sympy/core/expr.py in __float__(self)
219 # to fail, and if it is we still need to check that it evalf'ed to
220 # a number.
--> 221 result = self.evalf()
222 if result.is_Number:
223 return float(result)
/users/vishnu/anaconda3/lib/python3.5/site-packages/sympy/core/evalf.py in evalf(self, n, subs, maxn, chop, strict, quad, verbose)
1359
1360 """
-> 1361 from sympy import Float, Number
1362 n = n if n is not None else 15
1363
/users/vishnu/anaconda3/lib/python3.5/importlib/_bootstrap.py in _handle_fromlist(module, fromlist, import_)
SystemError: <built-in function hasattr> returned a result with an error set
예, I이 작동 개의 타원과의 사이의 최단 거리를 추정하고 싶었 다음은 그 예이다. 감사. 처음에는 최단 거리를 수치로 계산할 때 0에서 2 * pi 사이의 경계를 넣지 않은 이유는 확실하지 않지만 이제는 명확합니다. – Vishnu