Too many output arguments??? in nonlinear constraint function in ga

This is my nonlinear constraint function in ga built-in function,

function ceq=nonlincon(z)

ceq=z(3).*exp(z(2).*(1-z(1)))-1;

I am curious i obtain the error message:

Error using nonlincon Too many output arguments.

Error in createAnonymousFcn>@(x)fcn(x,FcnArgs{:}) (line 11) fcn_handle = @(x) fcn(x,FcnArgs{:});

Error in constrValidate (line 22) [tmpCineq,tmpCeq] = nonlcon([Iterate.x Iterate.x]');

Error in gacommon (line 136) [LinearConstr, Iterate,nineqcstr,neqcstr,ncstr] = constrValidate(NonconFcn, ...

Error in ga (line 319) [x,fval,exitFlag,output,population,scores,FitnessFcn,nvars,Aineq,bineq,Aeq,beq,lb,ub, ...

Error in Runfile (line 21) est=ga(h,3,[],[],[],[],[0 0 0],[1.0 10.0 1.0],contraint,options);

Caused by: Failure in initial user-supplied nonlinear constraint function evaluation.

WHY it is like that, i have only one output so far... Thanks!

[David Sanchez]

how are you calling your nonlincon function?

Answer 1

[Walter Roberson]

The non-linear constraint function is required to have two outputs, one for equality constraints and one for inequalities. If you do not wish to use one of the types of constraint, set the output for it to []

[Khoo]

So how to write the code instead? Is it something like

function [[],ceq]=nonlinconst(x)

I have tried this, it doesn't work as well.

[Khoo]

Ok i got it,

function [c,ceq]=nonlinconst(x)

c=inequality;

ceq=[];

Thanks!