First time user "can this optimization be solved with cvx"

Nonconvex
Mar 20, 2013
P

Hello,

it is first time I use the software and I would like to know if this problem can be rewritten somehow to be solved with cvx, or otherway it would be awesome if you can indicate me a program to try to get the solution. I get the error message

   ??? Error using ==> maximize at 36
Disciplined convex programming error:
   Cannot maximize a(n) convex expression.

Error in ==> semi at 17
maximize(x1^2+x2^2+x3^2)

the code is the following

cvx_begin sdp

variables x0 x1 x2 x3 y1 y2 y3 y4 y5

x0==1/sqrt(3)

1/3+x1^2+x2^2+x3^2+y1^2+y2^2+y3^2+y4^2+y5^2<=1

x1==-x3 
y1==y5
y2==-y4 

x0*X0+x1*X1+x2*X2+x3*X3+y1*Y1+y2*Y2+y3*Y3+y4*Y4+y5*Y5>=0

maximize(x1^2+x2^2+x3^2)

cvx_end

X0, X1,…X3,Y1,…Y5,Z1…Z7 (in capital letters) are matrices (spherical tensors) I pretend the product with the variables in lowercase to be positive semidefinite a constraint as well as the other equalities/inequalities after the variable statement.

M

No, quadratic maximizations are not convex. Please see this answer) for more information on using CVX properly.

P

ok, you know if there are any other resources to try to solve a nonconvex problem like that or is it hopeless?