Need help. Cannot perform the operation: {positive constant} ./ {convex}

1 
cvx_begin
	variable scheduling(K,N)   
	variable Q1(2,N)
	variable Slack_1(K,N)
	variable Slack_2(K,N)
	variable Slack_3(K,N) 
	variable t_traj_scheduling
	expressions Snr(K,N) Distant(K,N) R_traj_scheduling_lb(K,N) X_lb(K,N) Y_lb(K,N) E_lb(K,N) Slack_1_lb(K,N) Slack_2_lb(K,N) Z(K,1)       
	maximize ( t_traj_scheduling )
	for k=1:K
		Snr(k,:) = pow_pos((H^2+ pow_pos(norms( Q1(:,:)- BD_locat(:,k)*ones(1, N),2),2)),2) ./ (D.*B(k,:).*P_max);  %K*N
		Distant(k,:) = H^2+ pow_pos(norms( Q1(:,:)- BD_locat(:,k)*ones(1, N),2),2);
		Distant_lb(k,:) = H^2+ norms( Q1_r(:,:)- BD_locat(:,k)*ones(1, N),2).^2;
		
		Slack_1(k,:) = Band.*(log(1 + (D.*B(k,:).*P_max)./ pow_pos((H^2+pow_pos(norms( **Q1(:,:)**- BD_locat(:,k)*ones(1, N),2 ),2)),2))/log(2));%K*N

	end

Disciplined convex programming error:
Cannot perform the operation: {positive constant} ./ {convex}

error ./ (line 19)
z = times( x, y, ‘./’ );

error mainl_final (line 282)
Slack_1(k,:) = Band.*(log(1 + (D.*B(k,:).*P_max)./ pow_pos((H^2+pow_pos(norms( Q1(:,:)- BD_locat(:,k)*ones(1, N),2 ),2)),2))/log(2));%K*N

how to deal this problem？ help :pray:

2

I believe Slack_1 is neither convex nor concave, and therefore can’t be used in CVX.

But what do you do with Slack_1? The portion of the program in your post does not use it. If it is used in constraints, show us the constraints. Maybe you can multiply through the denominator for use in the constraints, and never explicitly form Slack_1.

BTW, the thread title has been edited because there is no need for theatrics. In the vast majority of threads, the poster needs help.

3

Thanks!!!
another problem:

		cvx_begin
		    expressions Snr_B(K,N) rate_B(K,N)
		    variable backscatter(K,N)      
		    variable t_backscatter             
		    maximize ( t_backscatter   )
		    subject to
		        for k=1:K
				    Snr_B(k,:) = (D.*backscatter(k,:).*P_max) ./ (( H^2+ norms( Q1_r(:,:)- BD_locat(:,k)*ones(1, N),2).^2 ).^2);
				    rate_B(k,:) =  log(1 + Snr_B(k,:))/log(2);
				end
				sum(Band.*assignment1.*rate_B, 2) ./ R_min >= t_backscatter  ;    
				0.8*sum((1-backscatter).*channel_0.*(ones(K,1)*(P_max*ones(1,N))), 2) >= Emin;
				0 <= backscatter;           
				backscatter <= 1;
				0 <= t_backscatter;
        cvx_end

the result "t_backscatter " is Nan，how to deal ？
t_backscatter= NaN

4

Please post log output.