matlab - Merge 2nd to last columns for duplicates in 1st column -

i want merge a's 2nd end column if a's 1st column duplicate

from

a = [2 3 1;      3 4 2;      2 6 8] 

to

b{1}=2 3 1 6   8 b{2}=3 4 2 nan nan 

or

b = [2 3 1 6    8;      3 4 2 nan nan] 

row ordering doesn't matter.

my first plan was

a=sortrows(a,1); % sort 1st col 

and divide various matrices according 1st col (i.e. different matrix different 1st column element)

then horzcat each 2:end elements each matrices.

and join them 1 object in way.

this plan or imagination though can't figure out if possible.

here method started. pad 0 instead of nan though:

b = sortrows(a,1); c = b(1,:);      row = 2:size(b,1)     if b(row,1) == c(end,1)         c(end, end+1:end+2) = b(row, 2:3);     else         c(end+1, 1:3) = b(row, :);     end end 

or same thing using cell array , not have pad @ all:

b = sortrows(a,1); c = {b(1,:)};      row = 2:size(b,1)     if b(row,1) == c{end}(1)         c{end}(end+1:end+2) = b(row, 2:3);     else         c{end+1} = b(row, :);     end end