How to join two matrices based on similar array in each

Matrix A as follows:

A = [
1  35  24  234  243
2  34  234  2  234
2  34  234  2  234
3  34  234  234  12
4  32  324  243  85
4  32  324  243  85
4  32  324  243  85
5  43  234  24  56
5  43  234  24  56
];

Matrix B as follows:

B = [43  65  1
45  546  5
43  6456  2
34  534  3
53  46  4
];

Based on the similar array in column 3 of matrix b and column 1 in matrix A, I want to joint these to matrix.

C = [
43  65  1  35  24  234  243
45  546  5  34  234  2  234
43  6456  2  34  234  2  234
34  534  3  34  234  234  12
53  46  4  32  324  243  85
];

Answer 1

[the cyclist]

Here is one way:

uniqueA = unique(A,'rows');
[~,idx] = ismember(B(:,3),uniqueA(:,1));
C = [B,uniqueA(idx,2:end)];

I am making a couple assumptions here, based on your one example:

• The rows in A with the same values in the first column are also identical throughout.
• Every value in B(:,3) is represented in A(:,1)

Answer 2

[Image Analyst]

I'm not really sure of your rule about "similar", but this seems to give you the output you gave:

A = [
1  35  24  234  243
2  34  234  2  234
2  34  234  2  234
3  34  234  234  12
4  32  324  243  85
4  32  324  243  85
4  32  324  243  85
5  43  234  24  56
5  43  234  24  56
]
[rowsA, columnsA] = size(A)

% Matrix B as follows:
B = [43  65  1
45  546  5
43  6456  2
34  534  3
53  46  4
]
[rowsB, columnsB] = size(B)

C = A(1:rowsB, 2:end); % Initialize.
C = [B C]