Could anybody tell me the working of coding

clear all;
clc;
N_UE=[10 20 30 40 50];
N_SC=[60 70 80 90 100];
for t= 1:length(N_UE)
for r = 1:length(N_SC)
 C=rand(N_UE(t),N_SC(r));
N_G=4;%No of group
B = cell(N_G,1);
sumB = cell(N_G,1);
C_copy = C;
for d=1:1:N_G
                if d==N_G
                    sz=length(C_copy(:,1));
                    e=sz;
                else
                    if d==1
                        e=randi([1 5]);% select No of UE randomly
                    else
                        sz=length(C_copy(:,1));
                        sz=ceil(sz/2);
                        e=randi([1 sz]);% select No of UE randomly

                      end
                  end
                  idx=randsample(1:size(C_copy,1),e);
                  B{d} = C_copy(idx,:);
                  C_copy(idx,:) = [];
                  [rows, columns] = size(B{d});
                  % Get sum of columns and replicate vertically.
                  sumB{d} = repmat(sum(B{d},1), [rows, 1]);
  end
  %               E=[sumB{1}; sumB{2};sumB{3};sumB{4};sumB{5};sumB{6};sumB{7};sumB{8};sumB{9};sumB{10}];
                E=[sumB{1}; sumB{2};sumB{3};sumB{4}];
      end
  end

Answer 1

[Walter Roberson]

As I posted before, you need to put an upper bound on the number of items you randomly select, and the upper bound needs to be (number of remaining groups minus 1)

I guess I needed to be more explicit: in your code, the number of remaining groups is (N_G - d)

[Prabha Kumaresan]

could you help me to write with the upper bound.

[Walter Roberson]

Change

sz=ceil(sz/2);

to

sz = min(ceil(sz/2), (N_G-d-1));

[Prabha Kumaresan]

If i change to sz = min(ceil(sz/2), (N_G-d-1)); it results in Error using randi First input must be a positive scalar integer value IMAX, or two integer values [IMIN IMAX] with IMIN less than or equal to IMAX.

Error in line e=randi([1 sz]);% select No of UE randomly.