python scipy 求解简单线性方程组和fmin求函数最小值 - Kermit.Li

python scipy 求解简单线性方程组和fmin求函数最小值

###这是一个利用内置函数求最小值#####
def func(x):
    return x ** 2 - 2 *x

x = 1
func(x)
opt.fmin(func ,x)

## 用scipy求解线性方程组
from scipy.optimize import fsolve
from math import sin, cos

def f(x):
    x0 = float(x[0])
    x1 = float(x[1])
    x2 = float(x[2])
    
    return [5 * x1 + 3, 
            4 * x0 * x0-2 * sin(x1 * x2),
            x1 * x2 -1.5]
def J(x):
    x0 = float(x[0])
    x1 = float(x[1])
    x2 = float(x[2])
    
    return[[0, 5, 0],
           [8 * x0, -2*x2*cos(x1*x2),-2*x1*cos(x1*x2)],
           [0, x2,x1]]
result = fsolve(f, [1,1,1],fprime = J)
print result
print f(result)