Extracting part of a matrix

Question

I have a matrix say (𝗉+𝗊) 𝗑 𝗋 order, I want to extract first 𝗉 𝗑 𝗋 order matrix, like say

,

I want to extract first

Answer 1

As suggested by rahnema1, you can use Matrix Indexing in matlab as follows:

partA = A(1:p, :)

or for your specific example:

partA = A(1:3, :)

Explanation

• 1:p: selects all rows between 1 and p.
• : selects all columns.

Further reading

As this seems a basic question to me, it may be useful to have a look at the Getting Started tutorial.