I've trying to use manopt to solve a cost function of the form:
with x, the vectorization of X, an X matrix in the Stiefel Manifold. The mapping between the manifold and the tangent space is exponential.
for this function, the gradient in the Stiefel Manifold is a 3x1 matrix, and the hessian is 3x3.
I tried using the next lines, but I get an error due to the size of the gradient
M = stiefelfactory(3, 3);
problem.M = M;
problem.costgrad = @(X)fandGrad(X,A,b,c);
problem.hess = @(X,u)Hessf(X,u,store);
[x_opt cost_opt info] = trustregions(problem, X0, options);
Is this the correct way to use the toolbox?
Do you have any suggestions to overcome this problem?
Thank you in advance.