# -*- coding: UTF-8 -*- """ @Project :onestar @File :minimize.py @Contact: @Author :SHJ @Date :2021/11/24 15:46 @Version :1.0.0 """ from scipy.optimize import minimize import numpy as np from mpl_toolkits.mplot3d import Axes3D from matplotlib import pyplot as plt #目标函数: def func(args): fun = lambda x: 10 - x[0]**2 - x[1]**2 return fun #约束条件,包括等式约束和不等式约束 def con(args): cons = ({'type': 'ineq', 'fun': lambda x: x[1]-x[0]**2}, {'type': 'eq', 'fun': lambda x: x[0]+x[1]}) return cons #画三维模式图 def draw3D(): fig = plt.figure() ax = Axes3D(fig) x_arange = np.arange(-5.0, 5.0) y_arange = np.arange(-5.0, 5.0) X, Y = np.meshgrid(x_arange, y_arange) Z1 = 10 - X**2 - Y**2 Z2 = Y - X**2 Z3 = X + Y plt.xlabel('x') plt.ylabel('y') ax.plot_surface(X, Y, Z1, rstride=1, cstride=1, cmap='rainbow') ax.plot_surface(X, Y, Z2, rstride=1, cstride=1, cmap='rainbow') ax.plot_surface(X, Y, Z3, rstride=1, cstride=1, cmap='rainbow') plt.show() #画等高线图 def drawContour(): x_arange = np.linspace(-3.0, 4.0, 256) y_arange = np.linspace(-3.0, 4.0, 256) X, Y = np.meshgrid(x_arange, y_arange) Z1 = 10 - X**2 - Y**2 Z2 = Y - X**2 Z3 = X + Y plt.xlabel('x') plt.ylabel('y') plt.contourf(X, Y, Z1, 8, alpha=0.75, cmap='rainbow') plt.contourf(X, Y, Z2, 8, alpha=0.75, cmap='rainbow') plt.contourf(X, Y, Z3, 8, alpha=0.75, cmap='rainbow') C1 = plt.contour(X, Y, Z1, 8, colors='black') C2 = plt.contour(X, Y, Z2, 8, colors='blue') C3 = plt.contour(X, Y, Z3, 8, colors='red') plt.clabel(C1, inline=1, fontsize=10) plt.clabel(C2, inline=1, fontsize=10) plt.clabel(C3, inline=1, fontsize=10) plt.show() # 目标函数: def func1(args): fun = lambda x: 10 - x[0] ** 2 - x[1] ** 2 return fun def samper(): args = () args1 = () cons = con(args1) x0 = np.array((1.0, 2.0)) #设置初始值,初始值的设置很重要,很容易收敛到另外的极值点中,建议多试几个值 #求解# res = minimize(func(args), x0, method='SLSQP', constraints=cons) ##### print(res.fun) print(res.success) print(res.x) # draw3D() drawContour() def samper1(): fun = lambda x: np.abs(np.abs((0.7- (x[0] -0.49)**0.5)/(0.7- (x[0] +0.49)**0.5)) - 0.5*np.abs((0.7- (x[1] -0.49)**0.5)/(0.7- (x[1] +0.49)**0.5))) # fun = lambda x: np.abs(x[0]**2 -x[1]**2) x_min = 1 x_max = 20 cons = ({'type': 'ineq', 'fun': lambda x: x[0] - x_min}, {'type': 'ineq', 'fun': lambda x: -x[0] + x_max}, {'type': 'ineq', 'fun': lambda x: x[1] - x_min}, {'type': 'ineq', 'fun': lambda x: -x[1] + x_max}) bnds = ((0, 30), (0, 30)) res = minimize(fun, (3, 3), method='SLSQP', bounds=bnds,constraints=cons) print("res::",res) x_arange = np.linspace(0, 25, 256) y_arange = np.linspace(0, 25, 256) X, Y = np.meshgrid(x_arange, y_arange) Z1 = np.abs(np.abs((0.7- (X -0.49)**0.5)/(0.7- (X +0.49)**0.5)) - 0.5*np.abs((0.7- (Y -0.49)**0.5)/(0.7- (Y +0.49)**0.5))) # Z1 = np.abs(X**2 - Y**2) plt.xlabel('x') plt.ylabel('y') plt.contourf(X, Y, Z1, 8, alpha=0.75, cmap='rainbow') C1 = plt.contour(X, Y, Z1, 8, colors='black') plt.clabel(C1, inline=1, fontsize=10) plt.show() if __name__ == "__main__": # samper1() s1 = 0.9414927 c1 = 0.24188292 s2 = 0.9414927 c2 = 0.24188292 t = 1.0 x_min = 1 x_max = 20 bnds = ((x_min, x_max), (x_min, x_max)) x_mid = 0.5 * (x_max - x_min) x = [9,8] a = (s2 - x[1]*(1 + s2)) b = np.abs((x[1] - 1)*(s2 - x[1]*(1 + s2)) / (x[1] * c2 + (x[1] - s2) ** 0.5) ** 2)- t * np.abs((x[0] - 1)*(s1 - x[0]*(1 + s1)) / (x[0] * c1 + (x[0] - s1) ** 0.5) ** 2) fun = lambda x: np.abs( np.abs((x[1] - 1)*(s2 - x[1]*(1 + s2)) / (x[1] * c2 + (x[1] - s2) ** 0.5) ** 2) - t * np.abs((x[0] - 1)*(s1 - x[0]*(1 + s1)) / (x[0] * c1 + (x[0] - s1) ** 0.5) ** 2) ) res = minimize(fun, (x_mid, x_mid), method='SLSQP', bounds=bnds) print("res::", res) x_arange = np.linspace(0, 25, 256) y_arange = np.linspace(0, 25, 256) X, Y = np.meshgrid(x_arange, y_arange) Z1 = np.abs( np.abs((Y - 1)*(s2 - Y*(1 + s2)) / (Y * c2 + (Y - s2) ** 0.5) ** 2) - t * np.abs((X - 1)*(s1 - X*(1 + s1)) / (X * c1 + (X - s1) ** 0.5) ** 2) ) # Z1 = np.abs(X**2 - Y**2) plt.xlabel('x') plt.ylabel('y') plt.contourf(X, Y, Z1, 8, alpha=0.75, cmap='rainbow') C1 = plt.contour(X, Y, Z1, 8, colors='black') plt.clabel(C1, inline=1, fontsize=10) plt.show() print('done')