Задача 3. Минимизация негладкой функции

In [1]:

    

%matplotlib inline
import numpy as np
import scipy.optimize as optimize
import math
from matplotlib import pylab as plt


    

In [2]:

    

# заданная функция
def f(x):
    return np.sin(x/5.0) * np.exp(x/10.0) + 5 * np.exp (-x/2.0)
# функция принимает только целые значения
def h(x):
    return int(f(x))
x = np.arange(1,30.1,0.1)


    

In [3]:

    

plt.plot(x,[h(i) for i in x])
plt.plot(x,[f(i) for i in x])


    

    
Out[3]:





[<matplotlib.lines.Line2D at 0x8188908>]






    

In [4]:

    

result = []


    

In [5]:

    

x_bfg = 30
res = optimize.minimize(h,x_bfg,method="BFGS")
result.append(round(res.fun,2))


    

In [6]:

    

bounds = [(1.0,30.0)]
res = optimize.differential_evolution(h,bounds)
result.append(round(res.fun,2))
res


    

    
Out[6]:





     fun: -11.0
 message: 'Optimization terminated successfully.'
    nfev: 77
     nit: 4
 success: True
       x: array([ 24.73565827])

In [7]:

    

result


    

    
Out[7]:





[-5.0, -11.0]

In [8]:

    

file_obj = open('result-week3-Task3.txt', 'w')
file_obj.writelines(res + ' ' for res in map(str, result))
file_obj.close()


    

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