How to create a vector with elements randomly chosen from another vector?

Hello folks.

I have a column vector, each of whose elements is a row vector consisting of two elements (essentially a par):

a = [[A1 T1] ; [C1 G1] ; [T2 A2] ; [G2 C2]]

How do I create another vector with the size 1*N, whose elements are randomly chosen from "a" ?

Note: The elements of the resulting vector can be repeated.

Thank you.

Answer 1

[Steven Lord]

I have a column vector, each of whose elements is a row vector consisting of two elements

The common term for that is a matrix.

If you want to sample without replacement, use randperm to determine which rows of your matrix you want to include and then use subscripted indexing to extract the selected rows.

If you want to sample with replacement, use randi to generate the row indices then use subscripted indexing just like in the randperm (without replacement) case.