MATLAB: How to compare and combine two matrix

comparingfor loopmatrix

Hello
I'm new into matlab and could'nt find help to my problem.
I have two large dataset that I want to combine so that each line corresponds to right value. In my dataset every line has a unique id (matrix column 1) and i want to find the lines with same id in a two different dataset and combine them into one.
So:
How can I do a loop that compares a value in two different matrix and then writes the result as a new. The value that is compared is written only once in outcome.
Lets say I have matrix A1 and A2 and I want a loop that compares if the values in first row are the same in A1 and A2. If this happen it combines the lines to a new variable. So in this case I would compare the first value in first column –> in line 2 and line 4 the first number match–> Result is the lines added without the first column in variable 2.
A1 =
3 3 5 3
8 1 5 2
6 4 5 6
7 4 7 1
A2 =
6 3 5
8 4 3
9 7 9
7 5 1
Outcome A3=
8 1 5 2 4 3
7 4 7 1 5 1
I have a code already that compares the value but how to generate the matrix A3 in a loop.
[m,n] = size(A1);
for i = 1:n
    if isequal (A1(1,i),A2(1,i));
    B(i,:)=[A1(i,:),A2(i,:)];
    end
end
B
Cheers

Best Answer

idx=A1(:,1)==A2(:,1);
A3=[A1(idx,:),A2(idx,2:end)]
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