fsolve-输入和输出之间不匹配 [英] fsolve - mismatch between input and output

问题描述

我正在尝试解决带有三个未知数的方程组的问题.我可以通过for循环调用方程组，从而在MATLAB中使用fsolve和lsqnonlin获得解决方案.

I'm trying to solve an overdetmined system of equations with three unknowns. I'm able to get solution with fsolve and lsqnonlin in MATLAB by calling the system of equations through a for loop.

但是在使用scipy的python中，我收到以下错误消息:

But in python using scipy, I'm getting the following error message:

fsolve: there is a mismatch between the input and output shape of the 'func' argument 'fnz'

代码如下:

from xlrd import open_workbook
import numpy as np
from scipy import optimize
g = [0.5,1,1.5]
wb = open_workbook('EThetaValuesA.xlsx')
sheet=wb.sheet_by_index(0)
y=sheet.col_values(0,1)
t1=sheet.col_values(1,1)
t2=sheet.col_values(2,1)
t3=sheet.col_values(3,1)

def fnz(g):
    i=0
    sol=[0 for i in range(len(t1))]
    x1 = g[0]
    x2 = g[1]
    x3 = g[2]
    print len(t1)
    for i in range(len(t1)):
        # various set of t1,t2 and t3 gives the various eqns
        print i
        sol[i]=x1+t1[i]/(x2*t2[i]+x3*t3[i])-y[i]    
    return sol

Anz = optimize.fsolve(fnz,g)

print Anz

任何人都可以建议我错了吗?预先谢谢你.

Could anyone please suggest where I'm wrong? Thank you in advance.

推荐答案

该异常表示 fnz()函数调用的结果与输入的 g ，它是3个元素的列表，或者可以看作是形状为(3，)的 array .

The exception means that the result from fnz() function call does not has the same dimension as the input g, which is a list of 3 elements, or can be seen as an array of shape (3,).

为说明问题，如果我们定义:

To illustrate the problem, if we define:

def fnz(g):
    return [2,3,5]
Anz = optimize.fsolve(fnz,g)

不会有这样的例外.但这会:

There will not be such an exception. But this will:

def fnz(g):
    return [2,3,4,5]
Anz = optimize.fsolve(fnz,g)

fnz()的结果应该与 t1 的长度相同，我敢肯定它的长度超过3个元素.

The result from fnz() should have the same length as t1, which I am sure is longer than 3 elements.

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