fminunc is not working in my equation, can you help me with these errors? i am a beginner in matlab

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hizaki 2014-5-22

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评论： hizaki 2014-5-22

采纳的回答： Harshvardhan

hi.. i am trying to optimize this equation through matlab's fminunc

in the editor i typed:

function F = fun(x,e) 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

in the command line i typed the following and at the same time got results shown:

x0= [0,0]; [x, fval] = fminunc (@fun,x0); ??? Undefined function or variable 'e'.

Error in ==> fun at 2 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;

Error in ==> fminunc at 227 f = feval(funfcn{3},x,varargin{:});

Caused by: Failure in initial user-supplied objective function evaluation. FMINUNC cannot continue.

can you help me fix this?

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Harshvardhan 2014-5-22

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what are your variables in the function? x can be a vector and when plugged in F should evaluate to a scalar. By the looks of your function 'fun' that doesn't seem to be the case.

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Harshvardhan 2014-5-22

Please follow my previous comment clearly. its exp(6) and not exp^6 and exp(7) and not exp^7

hizaki 2014-5-22

在 MATLAB Online 中打开

oh i am sorry..the result is....

x0 = 0; [x, fval] = fminunc (@fun,x0) Warning: Gradient must be provided for trust-region algorithm; using line-search algorithm instead. > In fminunc at 347

Solver stopped prematurely.

fminunc stopped because it exceeded the function evaluation limit, options.MaxFunEvals = 100 (the default value).

x =

NaN

fval =

NaN

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