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I want element (3,2) from a matrix with size (4,4) to try the values of the first column from another matrix with size (3,3) one by one and at each time produce the new matrix. How can I do this ?

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Adi Nor
Adi Nor 2017-5-9
关闭： Stephen23 2017-5-10
For example: If I have matrix A and Matrix B:
A =
7 4 1
4 5 6
3 6 9
B =
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
I want element (3,2) from matrix B with size (4,4) to try the values of the first column from matrix A with size (3,3) one by one and at each time produce the new matrix. So, the output will be:
B =
0 0 0 0
0 0 7 0
0 0 0 0
0 0 0 0
B =
0 0 0 0
0 0 4 0
0 0 0 0
0 0 0 0
B =
0 0 0 0
0 0 3 0
0 0 0 0
0 0 0 0
How can I do this ?

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回答（1 个）

Geoff Hayes
Geoff Hayes 2017-5-9
Mahmoud - do you want to keep the updated B at each iteration, or just use it and then dispose of it?
for k=1:size(A,1)
B = zeros(4,4);
B(2,3) = A(k,1);
% do something with B
end
In the above, we iterate over each row in the first column of A and set the appropriate element of B with it.
Note how we use B(2,3) to access the element in the second row and third column of B (rather than the B(3,2) that you mention).
  2 个评论
Adi Nor
Adi Nor 2017-5-9
编辑：Adi Nor 2017-5-9
If I want also B(4,2) to take values from 2nd column in matrix A beside B(3,2) takes values of the 1st column of matrix A .. How can I do this ?
Geoff Hayes
Geoff Hayes 2017-5-10
Which value in the second column of A? You should be able to modify the above so that you can accomplish that task.

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