/*
 * sdpsol specification for the matrix norm minimization problem:
 *   min \| A_0 + \sum_{i} x_i A_i \|
 *
 * See:
 *   L. Vandenberghe and S. Boyd, "Semidefinite Programming", Submitted
 *   SIAM review, July 1994, Sec. 2
 */

A0 = [1 , 0; 0, 1];
A1 = [-1, 2; 0,-3];
A2 = [0 ,-4; 7, 1];
A3 = [0 , 1;-1, 0];

variable x(3,1), t;

A = reshape([A0, A1, A2, A3],4,4);
Ax = reshape(A*[1;x],2,2);             /* gives A(x) */

constraint PD    [t*eye(2,2), Ax;
                  Ax',        t*eye(2,2)] > 0;

minimize mtrx_nrm = t;