# How to add a constant value above a matrix in following code?

2 views (last 30 days)
Nisar Ahmed on 7 Nov 2022
Answered: Steven Lord on 7 Nov 2022
Hello
P is a matrix of 100 106 and I am trying to add 20 constant values (say 0.25) above each row and 20 constant values (say 0.21) below each rows to make P as 140 106. How I can change following code? instead of taking first value of each column (P(1,:)), how I can replace with a constant value?
A_pad = zeros(140,106);
A_pad(1:20,:) = ones(20,1)*P(1,:);
A_pad(21:120,:) = P;
A_pad(121:140,:) = ones(20,1)*P(end,:);
##### 0 CommentsShow -2 older commentsHide -2 older comments

Sign in to comment.

### Accepted Answer

Torsten on 7 Nov 2022
P = [0.25*ones(20,106);P;0.21*ones(20,106)]
##### 0 CommentsShow -2 older commentsHide -2 older comments

Sign in to comment.

### More Answers (1)

Steven Lord on 7 Nov 2022
A = magic(4)
A = 4×4
16 2 3 13 5 11 10 8 9 7 6 12 4 14 15 1
B = [repmat(-999, 2, width(A));
A;
repmat(Inf, 3, width(A))]
B = 9×4
-999 -999 -999 -999 -999 -999 -999 -999 16 2 3 13 5 11 10 8 9 7 6 12 4 14 15 1 Inf Inf Inf Inf Inf Inf Inf Inf Inf Inf Inf Inf
This pads 2 rows containing the constant -999 above the matrix A and 3 rows containing the constant Inf below.
##### 0 CommentsShow -2 older commentsHide -2 older comments

Sign in to comment.

### 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!