How do you create a matrix of matrices in a method?

I'm trying to design a class whose instance is an array of matrices. The matrices are read from some source file, xls, csv, etc. The super matrix is of size 30, and the user can add files in each slot. The declaration needs to allow for dynamic possibilities. But I'm not sure how to do this syntactically. I'm running MATLAB R2012B.

Here is the code thus far:

classdef BankAccount < handle properties (Hidden) end

    properties (SetAccess = private)
        VEC
        IndicatorCount = 0;
        Index = zeros(30);   %This obviously won't work because of a dimension mismatch
    end

    methods
        function BA = BankAccount(filename)
            if nargin ~=0  %handles empty declarations
                BA.VEC = xlsread(filename);
                BA.IndicatorCount = FI.IndicatorCount +1; %find shorthand
                disp(FI.IndicatorCount)
                BA.Index(FI.IndicatorCount)= FI.VEC; %need the Index to be able to take on   %different matrix sizes dynamically

            end
        end
    end
end

if someone can tell me how to do this in a smart way I would appreciate the help

Answer 1

[Cedric]

Leaving aside OOP, we can say the following:

In your code, FI should be BA (the object) and you should replace Index=zeros(30); with Index=cell(30,1); to create a cell array, and then replace

 BA.Index(FI.IndicatorCount)= FI.VEC ;

with

 BA.Index{BA.IndicatorCount}= BA.VEC ;

Then you should type

 >> doc cell

in your command window and read a bit about cells and cell arrays, and maybe also have a look at my answer there: http://www.mathworks.com/matlabcentral/answers/58977-is-used-as-index-array-in-class so you have a better understanding of cell arrays.

Now about OOP

You cannot implement the code that adds elements to BA.Index in the constructor (method BankAccount), because it will be called only once when the class is instantiated (when the object is created). What you should have is a constructor that initializes relevant properties, and additional methods that can be called to perform actions, like adding/updating data/properties. For example:

 properties
    accountsCounter
    accounts
 end
 methods
    function obj = BankAccount( filename )    % Constructor.
       obj.accountsCounter = 0 ;
       obj.accounts = cell( 30, 1 ) ;         % Prealloc for 30 accounts.
       if nargin
          obj.add( filename )
       end
    end
    function add( obj, filename )
       obj.accountsCounter = obj.accountsCounter + 1 ;
       obj.accounts{obj.accountsCounter} = xlsread( filename ) ;
    end
 end

With that you can create an account or not when you create the object:

 >> ba = BankAccount() ;

or

 >> ba = BankAccount( 'JohnDoe.xlsx' ) ;

And then add accounts using the add() method:

 >> ba.add( 'MrSmith.xlsx' ) ;

.. and you can access "manually" properties just to check the functioning:

 >> ba

or

 >> ba.accounts{1}

[Jordan Ledvina]

Thanks Cedric,

you're the best!