How to code the following?

I have the following equation that i want to solve,
x*C -E -y = 0

Here, x and y are given; C and E are variables,
x’s size = (128,1),
C’s size = (1,2),
E’s size = (128,2),
y’s size = (128,2),

An important constraint other than the equation mentioned at first is that every row in E has to have the same value. That is E[0][0] = E[1][0] = E[2][0] = … = E[127][0] and
E[0][1] = E[2][1] = … = E[127][1]

How to frame the syntax for this in cvxpy (or cvx)? Answer mainly needed for cvxpy. Please help.

Here is CVX code. You should be able to do the equivalent in CVXPY.

variable E(128,2)
variable d(2)
E(:,1) == d(1)
E(:,2) == d(2)

Note that the RHS could instead be d(1)*ones(128,1) , d(2)*ones(128,1), Whether this kind of modification is needed for CVXPY is for you to determine.

Here is a different way of doing it in CVX.

variable d(1,2)
E = repmat(d,128,1)

This second way might be faster because it has fewer variables and constraints.

1 Like

Please could you give me the cvxpy code as well because I’m a beginner and I’m kinda lost. Please help.

This is not the appropriate place for CVXPY assistance. You should be able to apply one or the other of the ideas I showed to CVXPY. If you need more specific CVXPY assistance, you will have to request assistance on one of the CVXPY support locations.

1 Like

Thanks for letting me know. Appreciate your patience.