Build 2-D array with same 1-D array

I want to build a 2-D array with the same 1-D array. To say:

1-D array: [1 2 3 4 5 6]

to build a 2-D array like [1 2 3 4 5 6; 1 2 3 4 5 6; 1 2 3 4 5 6; 1 2 3 4 5 6; ...; 1 2 3 4 5 6;]

The total number of rows is determined by me. Is there any easy functions to implement to achieve this instead of using for loop?

Answer 1

[John BG]

hi Renuyan

yes, MATLAB has repmat

A=[1 2 3 4 5 4 6]

you set the amount of repetitions

reps=5

to replicate vertically:

repmat(A,reps,1)=
    1.00          2.00          3.00          4.00          5.00          6.00
    1.00          2.00          3.00          4.00          5.00          6.00
    1.00          2.00          3.00          4.00          5.00          6.00
    1.00          2.00          3.00          4.00          5.00          6.00
    1.00          2.00          3.00          4.00          5.00          6.00

replicating horizontally:

repmat(A,1,reps)=
  Columns 1 through 7
 1.00        2.00        3.00        4.00        5.00        6.00        1.00
  Columns 8 through 14
 2.00       3.00         4.00        5.00        6.00        1.00        2.00
  Columns 15 through 21
 3.00       4.00         5.00        6.00       1.00         2.00        3.00
  Columns 22 through 28
 4.00      5.00          6.00        1.00       2.00        3.00         4.00
  Columns 29 through 30
 5.00          6.00

so far the answer, but in similar exercises you may find also useful the command reshape. Let's say you want to stack A, either

A'

A'=
          1.00
          2.00
          3.00
          4.00
          5.00
          6.00

or

reshape(A,[6,1]) =
          1.00
          2.00
          3.00
          4.00
          5.00
          6.00

If you find this answer of any help solving your question, please click on the thumbs-up vote link,

thanks in advance

John

[e-mail]

[Renyuan Zhang]

Thanks, John.

Answer 2

[Walter Roberson]

repmat()

[Renyuan Zhang]

Thanks, Walter.