What is the name of the operation X(:)

I came across some code at work where they use X(:). It appears that this command rearranges the matrix. If I have a matrix X of size (M, N), then X(:) is of size (M*N,1).

What is the name of this operation? What can I search for?

I'm curious to read about it. One thing I want to check is if I can find an easy way to get the (M,N)-sized matrix back.

Thanks!

Answer 1

[Guillaume]

doc colon

[Björn]

Thanks!

[Guillaume]

Note that if you want to get the original matrix back, reshape is the function:

reshape(X(:), M, N)

Answer 2

[Matt J]

What is the name of this operation? What can I search for?

As it happens, the name of the operation and where you can read about it are two different things. Although X(:) is described under "doc colon", it is really a subsref operation,

>> X=rand(5,4);
>> S.type='()'; S. subs={':'};

>> isequal(X(:), subsref(X,S) )

ans =

       1