Fsolve - mismatch between input and output
I am trying to solve an overdetermined system of equations with three unknowns. I can get a solution with fsolve and lsqnonlin in MATLAB by calling the system of equations through a for loop.
But in python using scipy I get the following error message:
fsolve: there is a mismatch between the input and output shape of the 'func' argument 'fnz'
The code is below:
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
Could you please suggest where I am going wrong? Thank you in advance.
source to share
An exception means that the result of the function call fnz()
does not have the same size as the input g
, which is a list of three elements or can be thought of as array
forms (3,)
.
To illustrate the problem, if we define:
def fnz(g):
return [2,3,5]
Anz = optimize.fsolve(fnz,g)
There will be no such exception. But it will:
def fnz(g):
return [2,3,4,5]
Anz = optimize.fsolve(fnz,g)
The result from fnz()
should be the same length as t1
, which I'm sure is longer than three elements.
source to share