# [Matlab] Error running optimization.

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1. May 21, 2014

### karate

Error running optimization. Inputs must be a scalar and a square matri

I am trying to use fminunc using optimtool. But i got the error

Error running optimization.
Inputs must be a scalar and a square matrix.

this is the function i typed in the editor.

function F = fun(x)
F = -0.2662*x^6 + 48.19*x^5 - 3424.2*x^4 + 121708*x^3 - 2*e^6*x^2 + 2*e^7*x - 6*e^7;
end

i am not sure if this is a simple problem in matlab..i just want to optimize it using fminunc..i am new to matlab and there are a lot of things i do not understand.can you help me?

2. May 22, 2014

### Staff: Mentor

Could you please post the code where you call fminunc?

3. May 22, 2014

### FactChecker

Not sure if the error message is related to this error that you are making. You are trying to find the unconstrained minimum of a polynomial whose largest power term is -0.2662*x^6. This has no minimum. It goes down to -infinity.

If you fix that and still have a problem you should show how you are calling fminunc.

4. May 22, 2014

### karate

sir what method did you use to find that the term -0.2662*x^6 has no minimum?

5. May 22, 2014

### kreil

Last edited: May 22, 2014
6. May 23, 2014

### FactChecker

For unconstrained large values of x, x^6 is even larger. -0.2662*x^6 is unbounded negative and has no minimum.