Repeat matrix element of a given matrix

my matrix is x=[2 5 3 6 1]

I want it to make it as y=[2 2 2 2 5 5 5 5 3 3 3 3 6 6 6 6 1 1 1 1]

which function does it?

[Jan]

This topic is discussed such frequently, that I miss it in the FAQ.

Answer 1

[Jan]

x = [2 5 3 6 1];
y = reshape(repmat(x, 4, 1), 1, []);

Or:

y = kron(x, ones(1, 4));

[Nikhil Chourasia]

Thank you Jan Simon

[Nikhil Chourasia]

Hi Jan Simon can you help me to regain x from y. I have used kron in my coding.

[Guillaume]

That would be

x = y(1:4:end);

This is basic matrix indexing.

In the future, start a new question rather than asking in comments.

Answer 2

[Stephen23]

Another quick one-liner:

reshape(ones(4,1)*x,1,[])

[Nikhil Chourasia]

Thank you Stephen Cobeldick

[Nikhil Chourasia]

Hi Stephen Cobeldick can you help me to regain original matrix

Answer 3

[Guillaume]

New in 2015a, repelem:

repelem(x, 4)

[Nikhil Chourasia]

thank you Guillaume.

Answer 4

[Andrei Bobrov]

x = [2 5 3 6 1];
y = x(ceil((1:4*numel(x))/4));

[Nikhil Chourasia]

Thank You Andrei Bobrov

[Nikhil Chourasia]

Hi Andrei Bobrov can you help me to regain x from y

[Andrei Bobrov]

x = unique(y);