I want to do bootstrap analysis by using 20*1 matrix.

I want to draw 500 samples from the 20*1 matrix (20 pairs of observations).

In this case, what codes do I have to use?

Answer 1

[the cyclist]

One way is

% Pretend input data
M = rand(20,1);

idx = randi(20,500,1);
samples = M(idx);

Answer 2

[the cyclist]

If you have the Statistics and Machine Learning Toolbox, you can do

% Pretend input data
M = rand(20,1);

samples = randsample(M,500,true);