Extract subsets of consecutive entries in a matrix

I have an n x p matrix, A, of multivariate data. (n - data points, p - independent variables).

I want to select random subsets (i.e. extract collections of rows) from this data of size (p+1). The subsets need to be comprised of rows that are consecutive.

For example:

matrix = rand(100,4);
%n = 100, n data points
%p = 4, p independent variables

I want to create a random subset of 5 rows (p+1 = 5). So, rows 1 through 5 or 43 through 47, etc.

I know there are functions like randsample and datasample but I'm not sure how to use these to get subsets of rows that are together and not chosen at random throughout the matrix.

Answer 1

[Walter Roberson]

n = 100

n = 100

p = 4;
matrix = rand(n, p);
selected = select_consecutive_rows(matrix, p+1);
selected

selected = 5×4

0.9500 0.3396 0.5564 0.5069 0.4703 0.4893 0.0263 0.5017 0.7375 0.5300 0.5425 0.3738 0.8417 0.3768 0.0314 0.1109 0.0088 0.1602 0.9851 0.8399

function selected = select_consecutive_rows(matrix, p)
   idx = randi(size(matrix,1)-p+1);
   selected = matrix(idx:idx+p-1, :);
end

[Zavian Buchanan]

Thank you Walter! This works well.