Naming matrices in a for loop

Hi all,

I have a for loop that runs from 1 to 6. Within that for loop I am creating 2 matrices:

         for F = 1:6
         A = zeros(3,20);
         B = zeros(3,20);
         end

I have just used zeros(3,20) for example purposes. The actual matrices are not zero matrices. The matrices are dependant on other variables which change with F. So when I run the for loop I get 6 A matrices and 6 B matrices. My question is, is there a way of changing the names of these matrices that doesn't involve a long code. I was hoping to change them to something as simple as A1, A2, A3... B1, B2, B3...

I am trying to avoid having a large code.

Thanks in advance!

[Stephen23]

" as simple as A1, A2, A3... B1, B2, B3..." is a really really bad idea that will make your code slow, ugly and buggy: Do not create dynamic variable names! Read this to know why creating dynamic variable names is poor programming practice, even though many beginners seem to think that it is a great idea:

http://www.mathworks.com/matlabcentral/answers/196952-how-to-create-new-variables-in-batches-with-strcat

Answer 1

[the cyclist]

Use cell arrays:

for F = 1:6
  A{F} = zeros(3,20);
  B{F} = zeros(3,20);
end

[Zena Assaad]

Thank you

[Image Analyst]

Cell arrays are complicated and confusing, especially to beginners. If you're going to use them, instead of 3D arrays like I suggested, then make sure you read and understand the FAQ: http://matlab.wikia.com/wiki/FAQ#What_is_a_cell_array.3F

Another easier option is to use an array of structures - you don't have to learn the intricacies of when to use braces and when to use parentheses like you do with cell arrays.

[the cyclist]

What Image Analyst says is certainly true. The best data type to store your data depends on a few considerations. For example, if all your matrices are a fixed size, then a numeric type makes sense. For example:

A = zeros(3,20,6);
for F = 1:6
  A(:,:,F) = rand(3,20);
end

When you can't do something that simple, other data types are useful. Those of us have been using MATLAB for a long time will probably choose a data type based on some combination of (a) how appropriate it is for the task at hand, and (b) how familiar we are with it from past use. Image Analyst might choose an array of structures, where I might choose to use a table.

It's good to at least scan the examples in the documentation, to begin gaining a sense of what is possible. It can be confusing at first, though!

[Zena Assaad]

Thank you all for your comments. They have been very helpful!

Answer 2

[Image Analyst]

See the FAQ http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F for why this is a bad idea. Just use a 2 or 3D array instead.