Hi everybody.

I’ve got a problem with the position of minimize in my cvx cycle.

Precisely, I have an interval matrix as jacobian.I’m using matlab and I built a cell J{k}, with k from 1 to 16 and every J is a 2x2 matrix.

```
alpha1 =.1
alpha0 =0.004;
beta1=.2;
beta0=0.004;
gamma1=.02;
gamma0=0.004;
delta1=.02;
delta0=0.004;
J{01}=[alpha0 -beta0 ; gamma0 delta0];
J{02}=[alpha1 -beta0 ; gamma0 delta0];
J{03}=[alpha0 -beta1 ; gamma0 delta0];
J{04}=[alpha1 -beta1 ; gamma0 delta0];
J{05}=[alpha0 -beta0 ; gamma1 delta0];
J{06}=[alpha1 -beta0 ; gamma1 delta0];
J{07}=[alpha0 -beta1 ; gamma1 delta0];
J{08}=[alpha1 -beta1 ; gamma1 delta0];
J{09}=[alpha0 -beta0 ; gamma0 delta1];
J{10}=[alpha1 -beta0 ; gamma0 delta1];
J{11}=[alpha0 -beta1 ; gamma0 delta1];
J{12}=[alpha1 -beta1 ; gamma0 delta1];
J{13}=[alpha0 -beta0 ; gamma1 delta1];
J{14}=[alpha1 -beta0 ; gamma1 delta1];
J{15}=[alpha0 -beta1 ; gamma1 delta1];
J{16}=[alpha1 -beta1 ; gamma1 delta1];
```

I have to study the vector v :

**v = min (evaluated in v) of the max(evaluated in J) of the norm (a + J*v**,

with a = 2x1 vector that changes its value at the end of every cycles of cvx.

I try this and it works.

```
cv begin
cvx_precision default
variables v(2,1) real;
expression G(length(J));
for kk=1:16
G(kk)=norm(J{kk}*v+a);
end
minimize max(G);
cvx_end
```

but if I try this:

```
cvx_begin
cvx_precision default
variables v(2,1) real;
expression G(length(J));
minimize max(G);
for kk=1:16
G(kk)=norm(J{kk}*v+a);
end
cvx_end
```

the cvx_optval (in all the cycles) are equal to zero, even though all G(kk) aren’t equal to zero.

Why the cvx gives me that value of optval?

Thank you a lot for your help

Luca