Clear Filters
Clear Filters

Add elements to a matrix

7 views (last 30 days)
stelios loizidis
stelios loizidis on 30 Dec 2020
Commented: stelios loizidis on 30 Dec 2020
Hello.
I have the following problem: I have a matrix A (3x3), and I want to add elements to this matrix and create table B with dimensions 6x6. More specifically, I want the new data to be the same as the original ones.
A=(1 2 3; 4 5 6; 7 8 9)
% A=(1 2 3
% 4 5 6
% 7 8 9)
B=(1 1 2 2 3 3; 4 4 5 5 6 6; 7 7 8 8 9 9)
% B=( 1 1 2 2 3 3
% 4 4 5 5 6 6
% 7 7 8 8 9 9)
That is, the first element of table A (1,1) is 1. Then, in positions (1,1) (1,2) of the new matrix (B) it must again be 1. In position A (1,2) it is 2, then in positions (1,3) and (1,4) of B to appear 2. Respectively with the other elements. How is this done? Your help is important.

Accepted Answer

Ameer Hamza
Ameer Hamza on 30 Dec 2020
Edited: Ameer Hamza on 30 Dec 2020
Use repelem()
A = [1 2 3; 4 5 6; 7 8 9]
B = repelem(A, 1, 2)
Note: In MATLAB [ ] are used to create arrays.
  6 Comments
Ameer Hamza
Ameer Hamza on 30 Dec 2020
In this case, try
A = [1 2 3; 4 5 6; 7 8 9]
B = repelem(A, 1, 4)
D = B.*repmat([1 1 -1 -1], size(A))
or as Steven mentioned,
A = [1 2 3; 4 5 6; 7 8 9]
D = kron(A, [1 1 -1 -1])
stelios loizidis
stelios loizidis on 30 Dec 2020
It works. Thank you very much!!!!

Sign in to comment.

More Answers (0)

Categories

Find more on Matrices and Arrays in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!