Matrix to Vector Conversion in Matlab

Question

I have a MxN Matrix and would like to convert into a vector MNx1 with all the elements of the row from the Matrix as the elements of the Vector.

I tried using reshape but I was not successful.

Here is the small code snippet and the expected result.

  S=[0     1
     1     0
     1     1
     1     1 ]

Expected Result:

S_prime= [ 0 1 1 0 1 1 1 1]

P.S: Using a loop and concatenation is not an option, I am sure there is a easy straight forward technique, which I am not aware.

Thanks

Solution 1

You could try transposing S and using (:)

S = S'
S_prime = S(:)

or for a row vector:

S_prime = S(:)'

Solution 2

Reshape takes the elements column wise so transpose S before reshaping.

>> reshape(S',1,[])

ans =

     0     1     1     0     1     1     1     1

Solution 3

reshape(S',1,prod(size(S)))

or shortcut

reshape(S',1,[])

But the question makes me wonder what your original problem is, and if this way really is part of the correct solution to the original problem.

Comments

[Kiran]

This is not what I am looking for, This is similar to writing S(:) I am looking for row-wise concatenation into a vector.

[Daniel Andersson]

OK, that makes me wonder even more about the original problem, but just transpose S and then use the methods. I'll edit my answer.

[Felix Ribeiro]

I think the problem was that just to reshape S as you have given it returns [0 1 1 1 1 0 1 1] which is different as row wise selection rather than column wise selection was requested.

[Kiran]

Thanks Adrian, Thanks a lot for your time and help. I wonder, why I didnot try taking the transpose. Thank you so much

[Norbert Madarász]

Is this S(:)' correct for a row vector? I think as a one liner, f'(:)' is the correct answer (at least testing with octave).

[EIIPII]

here is the octave documentation page about this feature: http://www.gnu.org/software/octave/doc/interpreter/Index-Exp‌​ressions.html#Index-‌​Expressions

[sammy]

I had the same experience as Norbert. S'(:)' gave a row vector. S(:)' gave a row vector, but the elements were added to it column-wise, not what I wanted.