i have to find optimal a by solving
minimize fi(a)-u l2(L(a)) …>i am sure it is a convex problem
subject to 0<=a<1

where a is square matrix and l2(L(a)) is second smallest eigen value of laplacian matrix ,u is positive real parameter.

while solving i need to write an expression k2=(a./(1-a)).^4 ---------eq 1
(fi(a) = sum of all elements of matrix k2),
how can i write 1st eq 1 inside cvx ?

while i was writing using inv_pos function i got errors Illegal operation: pow_p( {convex}, {-1} ) and y = pow_cvx( x, -1, ‘pow_p’ );

that was a convex function as i mentioned!!! while i am trying to write equation to solve k2 i am getting error Cannot perform the operation: {real affine} ./ {real affine}

Its convexity matters less than you think. You must be able to express it according to CVX’s specific rules; and if you cannot, CVX can’t handle it—even if it is convex.