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pythonarraysnumpynonlinear-functions

"Setting an array element with a sequence" error when using fsolve for a system of nonlinear equations

So I'm trying to solve a nonlinear system of 6 equations 6 unknowns using fsolve. I followed a format found here:

http://folk.uio.no/inf3330/scripting/doc/python/SciPy/tutorial/old/node18.html

My system of equations:

def func(x):

    out = [x[0] - c*(t1 - x[3])]
    out.append(x[1] - c*(t2 - x[3]))
    out.append(x[2] - c*(t3 - x[3]))
    out.append(x[0]**2 - (right_x - x[4])**2 - (right_y - x[5])**2)
    out.append(x[1]**2 - (middle_x - x[4])**2 - (middle_y - y[5])**2)
    out.append(x[2]**2 - (left_x - x[4])**2 - (left_y - x[5])**2)
    return out

solve = fsolve(func, [1.0, 1.0, 1.0, 1.5, 1.0, 1.0])
print(solve)

returns the error:

  File "C:\Anaconda3\lib\site-packages\numpy\core\numeric.py", line 525, in asanyarray
    return array(a, dtype, copy=False, order=order, subok=True)

ValueError: setting an array element with a sequence.

All constants are of dtype: float

Any ideas on what I'm doing wrong?

Solution

  • The one thing I can spot is that the y[5] here looks like a typo:

    out.append(x[1]**2 - (middle_x - x[4])**2 - (middle_y - y[5])**2)

    might y[5] in your context be something like a numpy array or similar?