i want to solve this problem using cvx，however it gives following results

it shows that the status is failed,i am not sure whether the error expression formulations used in cvx.

Question1: R_r_d is a matrix ,i want to use each element for compared other function,whether cvx can accepted written like this ?

Question2:i want to sum every element in R_r_d ,written like following is ok in cvx?

Question3:The constraint of R_r_d is each element should be >=0，whether can i directly written like following ?

Thanks in advance .

Because of your use of log, CVX"s successive approximation method has been invoked. Your model was accepted by CVX, but the output you showed indicates the solution failed. Please read the disclaimer at http://web.cvxr.com/cvx/doc/advanced.html#the-successive-approximation-method .

You should try all the solver options available to you, such as

`cvx_solver sdpt3`

or

`cvx_solver sedumi`

If you have MOSEK available, that may work better than sdpt3 or sedumi.

Alternatively, you may be able to avoid the use of the successive approximation method if you use CVX 3.0beta, and install and specify ecos or scs solvers, which have native support for the exponential cone. These should allow more reliable solution of your problem. ecos is more likely to quickly solve your problem given that it uses second order method, rather than first order method used by scs.