Create a vector name from two integer variables

Hi,

I want to create a vector name from two integer variables. For example I have two for loops

for i=1:N for j=1:M

and I want to create a vector called vectorij, i.e: vector12, vector 13 and so on. Thanks

[Traian Preda]

I tried some of your proposal but I got some other things :)

What I try it is I have a matrix of (N,M) which I want to split it in column vectors, called as vector(column, row) containg the values of the matrix (column,row)..

[Jan]

I do not understand, what you are looking for. Could you provide an explicit example with real data?

[Traian Preda]

For example:

I have the A matrix, which changes during 3 iterations like:

Iteration 1 A1=[1 2 3 4; 5 6 7 8];

Iteration 2 A2=[3 5 3 4; 6 6 7 9];

Iteration3 A3=[3 2 3 5; 1 6 4 8];

Then I want to obtain the equivalent vectors associated with the upper 3 matrices

vector11=[1,5]; vector12=[2,6]; .............. vector22=[5,6]; vector23=[3,7]; .............. vector33=[3,4]; vector34=[5,8];

and I want that my vector to have the name: vector_Iteration_No_Column A matrix for example vector34 is vector_Iteration3_Column4

Hope now is much clear :)

Answer 1

[James Tursa]

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

[Azzi Abdelmalek]

I think he is not asking for variables name, just a cell array of stings

[Jan]

No, "vector11=[1,5]" from the comment looks, like names are wanted.

Answer 2

[Jan]

Hiding the indices inside the names of variables is really cruel. Don't do this. You'd never do this in the real life. Names are names, data are data.

A{1} = [1 2 3 4; 5 6 7 8];
A{2} = [3 5 3 4; 6 6 7 9];
A{3} = [3 2 3 5; 1 6 4 8];

Now write instead of "vector11":

A{1}(:, 1)

Or general instead of "vector_ij_":

A{i}(:, j)

This is fast, easy to expand to billions of iterations and fast to process. Using a 3D-array might be even faster, if the elements of A have all the same size.

Answer 3

[Azzi Abdelmalek]

This is a vector of names

out={};
for k=1:5
  for p=1:5
      out{end+1}=sprintf('vector%d%d',k,p)
  end
end

[Sean de Wolski]

regexp(sprintf('vector%i%i\nS',fullfact([5 5])'),'S','split')'

:)

[Bajdar Nour]

What is mean by something like this name= []?

[Image Analyst]

It sets the variable called "name" to null, or empty. It still exists, it's just that it has no value at all. Doing that to a row of a matrix will delete that row from the matrix, shortening it.