group_ADMM_logistic.m

function [obj_GADMM, loss_GADMM, Iter, gadmm_time]=group_ADMM_logistic(XX,YY, rho, no_workers, num_feature, per_samples, num_iter, obj0, lambda_logistic, acc)

s1=num_feature;
s2=per_samples;
Iter = 100;

lambda = zeros(s1,no_workers);

%x1 = zeros(50,1);
%x2 = zeros(50,1);
out=zeros(s1,no_workers);
flagg =0;
max_iter = num_iter;
gadmm_time(1)=0;
 for i = 1:max_iter
     %i
     for ii =1:2:no_workers
         cvx_begin quiet
         %cvx_solver SDPT3%mosek
     %cvx_precision low%high%low
     variable x(s1)
     
         if ii==1
             C1 = zeros(s1,1);
             term_1 =0;
         else
             C1= lambda(:,ii-1);
             term_1=rho/2*sum_square(x-out(:,ii-1));
         end
         
         if ii == no_workers
             C2 = zeros(s1,1);
             term_2 = 0;
         else
             C2= lambda(:,ii);
             term_2 = rho/2*sum_square(x-out(:,ii+1));
             
         end
         first = (ii-1)*s2+1;
         last = first+s2-1;
        
         %ii
%         if(ii==15)
%             ii
%         end
        %cvx_solver mosek
            
        objFun=lambda_logistic*0.5*sum_square(x)+sum(log(1+exp(-YY(first:last).*(XX(first:last,1:s1)*x))))- C1'*x+C2'*x + term_1...
            +term_2;
        %minimize(0.5*sum_square(XX(first:last,1:s)*x - YY(first:last))- C1'*x+C2'*x + term_1+term_2)
        if(ii==1 && i > 1)
                tic
            end
            minimize(objFun)
         cvx_end
         
        if(ii==1 && i > 1)
            gadmm_time(i)=gadmm_time(i-1)+2*toc;
        end
        out(:,ii) =x;
        
     end
    
    
        
     for ii =2:2:no_workers
          cvx_begin quiet 
        %cvx_precision low %high%low
        %cvx_solver SDPT3%mosek
        variable x(s1)
         C1= lambda(:,ii-1);
         if ii == no_workers
             C2 = zeros(s1,1);
             term_2 = 0;
         else
             C2= lambda(:,ii);
             term_2 = rho/2*sum_square(x-out(:,ii+1));
         end
         term_1=rho/2*sum_square(x-out(:,ii-1));
         first = (ii-1)*s2+1;
         last = first+s2-1;
         
        objFun=lambda_logistic*0.5*sum_square(x)+sum(log(1+exp(-YY(first:last).*(XX(first:last,1:s1)*x))))- C1'*x+C2'*x + term_1...
            +term_2;
        minimize(objFun)
        cvx_end
        out(:,ii) =x;
     end
     
        for ii=1:no_workers-1
            lambda(:,ii) = lambda(:,ii) + rho*(out(:,ii)-out(:,ii+1));
            %lambda_2(:,ii) = lambda_2(:,ii) + rho*(out(:,ii)-out(:,ii+1));
            %gap(ii)=norm(out(:,ii)-out(:,ii+1))
        end
        
%         for ii=2:no_workers-1
%             lambda_2(:,ii) = lambda_2(:,ii) + rho*(out(:,ii)-out(:,ii+1));
%         end
        
        final_obj = 0;
        for ii =1:no_workers
            first = (ii-1)*s2+1;
            last = first+s2-1;
            %final_obj = final_obj + 0.5*sum_square(XX(first:last,1:s)*out(:,ii) - YY(first:last));
            final_obj = final_obj+lambda_logistic*0.5*norm(out(:,ii))^2+sum(log(1+exp(-YY(first:last).*(XX(first:last,1:s1)*out(:,ii)))));
        end
        i
        obj_GADMM(i)=final_obj
        loss_GADMM(i)=abs(final_obj-obj0)
       
        
        if(loss_GADMM(i) < acc)
            Iter = i;
            break;
        end
    

end