自学教程：python实现黄金分割法的示例代码

#黄金分割法python求解PPT上第一个例题#因为函数要求解最大值而这个方法一般求解最小值所以把函数取负import numpy as npimport matplotlib.pyplot as pltrate = 0.618034def f(x):    #求解体积函数公式，乘1.0将结果变为浮点数    return -1.0*x*(350-2*x)*(260-2*x)  def tarceback(f,a0,b0,accuracy):    a = a0    b = b0    x2 = a+rate*(b-a)    x1 = b-rate*(b-a)    f1 = f(x1)    f2 = f(x2)    print(x1,x2)    arr = search(f,a,b,x1,x2,f1,f2,accuracy)    printFunc(f,a,b,arr[0],arr[1])    def search(f,a,b,x1,x2,f1,f2,accuracy):    if f1<=f2:        if x2-a<accuracy:            print(x1,f1)            return (x1,f1)        else:            b = x2            x2 = x1            f2 = f1            x1 = a+b-x2            f1 = f(x1)            print(x1,x2)            return search(f,a,b,x1,x2,f1,f2,accuracy)    else:        if b-x1<accuracy:            print(x2,f2)            return (x2,f2)        else:            a = x1            x1 = x2            f1 = f2            x2 = a+b-x1            f2 = f(x2)            print(x1,x2)            return search(f,a,b,x1,x2,f1,f2,accuracy)def printFunc(f,a,b,x,y):    t = np.arange(a,b,0.01)    s = f(t)    plt.plot(t,s)    plt.plot([x],[y],'ro')    plt.plot([x,x],[y,0],'k--')    plt.plot([0,x],[y,y],'k--')#     plt.annotate(r'$(x,y)$',xy=(x,y))    plt.show()tarceback(f,0,130,0.05)