How do we express norm.(..)^3 or norm.(..)^4

1

As the title，we use the square_pos(norm(…)) replace norm.(…)^2 in the cvx.
If the norm.(…)^4 can be replaced by square_pos(norm(…))*square_pos(norm(…))?

2

pow_pos(norm(x),3)
pow_pos(norm(x),4)

help pow_pos

pow_pos Power of positive part.
pow_pos(X,P) = POS(X).^P = MAX(X,0).^P.
Both P and X must be real, and P must be greater than or equal to 1.

Disciplined convex programming information:
    pow_pos(X,P) is convex and nondecreasing in X; so when used in CVX
    expressions, X must be convex. P must be constant, real, and
    greater than or equal to 1.

square_pos(square_pos(norm(x))) also works for norm(x)^4.

1 Like
3

I get it.Thank you very much.