problem-based quadprog in R2017b

Hello, trying to solve a 2rd order min problem in R2017b using the problem-based methods. I'm getting Undefined function 'mpower' for input arguments of type 'optm.problemdef.OptimizationVariable'. Code below. I had a similar type problem using the online help which I believe is for a more recent version of MATLAB. I’m using R2017b. I prefer the problem-based approach – just seems less date entry error prone and I’m more of an object-oriented user.

x = optimvar('x',2);  % 
 

% Using quadratic programming
objec = 2*x(1) + x(2) - (x1)^2;   ! (error in this line)
prob = optimproblem('Objective',objec);

% Constraints 
prob.Constraints.cons1 = 2*x(1) + 3*x(2) <= 6;
prob.Constraints.cons2 = 2*x(1) + x(2)   <= 4;
prob.Constraints.cons3 = x(1) >= 0;
prob.Constraints.cons4 = x(2) >= 0;

problem = prob2struct(prob);
[x, fval] = quadprog(problem)

 Undefined function 'mpower' for input arguments of type 'optim.problemdef.OptimizationVariable'.

I’m following an example openExample('optim/QuadraticProblemFromProb2structExample')

But this isn’t in my version; I run the command with the following error

>> openExample('optim/QuadraticProblemFromProb2structExample')

Error using findExample (line 35)

Example "QuadraticProblemFromProb2structExample" not found in "C:\Program Files\MATLAB\R2017b\examples\optim\examples.xml".

Error in setupExample (line 5)

metadata = findExample(arg);

Error in openExample (line 10)

[metadata,workDir] = setupExample(varargin{:});

Questions are (1) how to fix the syntax, (2) is the help for R2017b accessible? Currently I hit Help and get R2018x, so it seems (I don’t know what x version is current), and (3) is it “better” to upgrade to the current MATLAB to work around the version-help mismatch?

Regards,

Jon

Answer 1

[Walter Roberson]

x1 is not defined . I suspect you have x(1)^2

R2018a and r2017b only support linear problems . Quadratic problems were not supported until r2018b .