Why am I getting this error??!! #fmincon

I am getting the following error in my MATLAB code. I have already checked i hvae these functions on my computer.

Check for missing argument or incorrect argument data type in call to function 'classifyBoundsOnVars'.

Error in fmincon (line 525)

xIndices = classifyBoundsOnVars(l,u,sizes.nVar,true);

Error in optm (line 7)

[x,fval] = fmincon(@optmequation,x0,[],[],[],[],[],[],@constraint,options)

[Athul Prakash]

Could you provide more details so that the community can have a look at your variables? How are you creating 'optmequation', 'constraint' and what is your options struct?

[hapa_kazi_tu]

I am receiving the same error message, using the latest version of MATLAB and the optimization toolbox.

Here is a short example that leads to the error: (from the documentation of fmincon)

fun = @(x) 100*(x(2)-x(1)^2)^2 + (1-x(1))^2;

x0 = [-1,2];
A = [1,2];
b = 1;
x = fmincon(fun,x0,A,b)

This is the result:

Check for missing argument or incorrect
argument data type in call to function
'classifyBoundsOnVars'.
Error in fmincon (line 525)
    xIndices =
    classifyBoundsOnVars(l,u,sizes.nVar,true);
    Error in example (line 6)
x = fmincon(fun,x0,A,b) 

[hapa_kazi_tu]

I solved it by myself :) For some reason there was a copy of fmincon.m in the same folder as the script, and this version seemed to be out of date.

[AquilesC]

Yep hapa_kazi_tu, your comment is correct !!!, don´t put any copy of fmincon.m in the same folder where the script is. I have had the same problem as you.

Answer 1

[Steve Grikschat]

This is likely due to an installation issue.

fmincon is part of Optimization Toolbox, and if you do not have the full installation, fmincon will be there but other internal functions (like classifyBoundsOnVars) may not.

Try calling

which -all classifyBoundsOnVars

If it is not there, then you need to (re-)install Optimization Toolbox.