MATLAB: Another data manipulation question,need some help!

data manipulation

There are two matrix A and B.
A =
          15         4534      0          31
          10         0         346        0
          10         342       124        11
          20         345       0          13 
          25         73        311        15
          15         0         0          14
          10         0         153        16
          15         532       129        19
          20         153       0          0
B =
                  10        4324      13976       7645
                  15        7675      3821        14510      
                  20        13198     0           3874
                  25        4321      4321         4321
According to the first column, replace the rest columns of A with B.
The result should be:
C =
                  15        7675      3821        14510 
                  10        4324      13976       7645
                  10        4324      13976       7645
                  20        13198     0           3874
                  25        4321      4321         4321
                  15        7675      3821        14510 
                  10        4324      13976       7645
                  15        7675      3821        14510 
                  20        13198     0           3874
I used 2 loops(shown as follows) to get the result. But I was wondering if there is an easier way.
C(:,1) = A(:,1);
              for i = 1: length(A)
                  for n = 1:length(B)
                      if A(i,1) ==B(n,1)
                          C(i,2:4) = B(n,2:4);
                      end
                  end
              end
Any suggestion is welcomed!

Best Answer

[tf, idx] = ismember( A(:,1), B(:,1) );
A(tf,:)= B(idx(tf), :);
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