Sorting a matrix according to another one

Dear all,

I have the following problem to solve.

clear
clc

% A matrix defined as follows
A=[11 0.001 3
   11 0.001 4
   12 0.003 5
   9  0.002 6
   8  0.000 7
   10 0.004 8
   8  0.000 9
   9  0.002 10];
% B matrix is the reference one
B=[8  0.000
   8  0.000
   9  0.002
   10 0.004
   9  0.002
   11 0.001
   11 0.001
   12 0.003];

I want to sort A such that the first two columns coincide with B (and sort the other A column in agreement with this, of course). I used this code, but the problem is that since in B I have repeted conditions the result is not the one I desire.

[~,Y]=ismember(A(:,1:2),B,'rows');
[~,Z]=sort(Y);
C=A(Z,:);
% C=8   0.000  7
%   8   0.000  9
%   9   0.002  6
%   9   0.002  10
%   10  0.004  8
%   11  0.001  3
%   11  0.001  4
%   12  0.003  5

But what I want is

% C=8   0.000  7
%   8   0.000  9
%   9   0.002  6
%   10  0.004  8
%   9   0.002  10
%   11  0.001  3
%   11  0.001  4
%   12  0.003  5

Do you have any suggestions that don't involve using nested loops and if conditions?

Thank you very much for your attention!

Mattia

[Torsten]

What if B has some equal rows (like e.g. [8 0] or [11 0.001]) ?

[Mattia Salomone]

Thanks for your answer. Well in this case the order in which they appear in C should be the one they have in A. In this case with [8 0], for example, I want

[8 0 7
 8 0 9]

Because in A they appear with this order.

Answer 1

[Torsten]

A = [11 0.001 3
     11 0.001 4
     12 0.003 5
     9  0.002 6
     8  0.000 7
     10 0.004 8
     8  0.000 9
     9  0.002 10];
% B matrix is the reference one
B = [8  0.000
    8  0.000
    9  0.002
    10 0.004
    9  0.002
    11 0.001
    11 0.001
    12 0.003];
[~,idx] = sortrows(A,[1 2]);
[~,jdx] = sortrows(B,[1 2]);
C = A(idx(jdx),:)

C = 8×3

8.0000 0 7.0000 8.0000 0 9.0000 9.0000 0.0020 6.0000 10.0000 0.0040 8.0000 9.0000 0.0020 10.0000 11.0000 0.0010 3.0000 11.0000 0.0010 4.0000 12.0000 0.0030 5.0000

[Mattia Salomone]

Thanks for your answer, however your solution works for this case, but for example if

B=[9  0.002
   8  0.000
   8  0.000
   10 0.004
   9  0.002
   11 0.001
   11 0.001
   12 0.003];

The output C has a different order:

C= 8.0000         0    9.0000
   9.0000    0.0020    6.0000
   8.0000         0    7.0000
   10.0000    0.0040    8.0000
   9.0000    0.0020   10.0000
   11.0000    0.0010    3.0000
   11.0000    0.0010    4.0000
   12.0000    0.0030    5.0000

[Torsten]

A=[11 0.001 3
   11 0.001 4
   12 0.003 5
   9  0.002 6
   8  0.000 7
   10 0.004 8
   8  0.000 9
   9  0.002 10];
% B matrix is the reference one
B=[8  0.000
   8  0.000
   9  0.002
   10 0.004
   9  0.002
   11 0.001
   11 0.001
   12 0.003];
Acopy = A;
C = zeros(size(A));
for i = 1:size(A,1)
  idx = find(Acopy(:,1:2)==B(i,:),1);
  C(i,:) = Acopy(idx,:);
  Acopy(idx,:) = [];
end
C

C = 8×3

8.0000 0 7.0000 8.0000 0 9.0000 9.0000 0.0020 6.0000 10.0000 0.0040 8.0000 9.0000 0.0020 10.0000 11.0000 0.0010 3.0000 11.0000 0.0010 4.0000 12.0000 0.0030 5.0000

[Mattia Salomone]

Thank you very much for your help!