How can we insert a row matrix without altering the rest of the values?

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Hi!
Say, I have this matrix -
A =
1 2 3
4 5 6
7 8 9
10 11 12
13 14 15
Now I want to add A*10 after each of the rows so that I can make this matrix -
A =
1 2 3
10 20 30
4 5 6
40 50 60
7 8 9
70 80 90
10 11 12
100 110 120
13 14 15
130 140 150
I have hundreds of rows, so I would prefer a loop (or anything!)
Thank you for your help.

Accepted Answer

Dyuman Joshi
Dyuman Joshi on 2 Dec 2022
Edited: Dyuman Joshi on 2 Dec 2022
A = reshape(1:15,3,5)'
A = 5×3
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
%pre-allocation
y=zeros(size(A,1)*2,size(A,2));
y(1:2:end,:)=A;
y(2:2:end,:)=A*10
y = 10×3
1 2 3 10 20 30 4 5 6 40 50 60 7 8 9 70 80 90 10 11 12 100 110 120 13 14 15 130 140 150

More Answers (1)

Fangjun Jiang
Fangjun Jiang on 2 Dec 2022
Edited: Fangjun Jiang on 2 Dec 2022
A=magic(3);
C=transpose(reshape([A,10*A]',size(A,1),[]))
C = 6×3
8 1 6 80 10 60 3 5 7 30 50 70 4 9 2 40 90 20

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