Programming and Data Types

The Portfolio subsref Method

When MATLAB encounters a subscripted reference, such as that made in the getAccountNumber function

p.name(1:3)

MATLAB calls the portfolio subsref method to interpret the reference. If you do not define a subsref method, the above statement is undefined for portfolio objects (recall that here p is an object, not just a structure).

The portfolio subsref method must support field-name and numeric indexing for the getAccountNumber function to access the portfolio name field.

function b = subsref(p,index)
% SUBSREF Define field name indexing for portfolio objects
switch index(1).type
case '.'
    switch index(1).subs
    case 'name'
        if length(index)== 1
            b = p.name;
        else
            switch index(2).type
            case '()'
                 b = p.name(index(2).subs{:});
            end
        end
    end
end

Note that the portfolio implementation of subsref is designed to provide access to specific elements of the name field; it is not a general implementation that provides access to all structure data, such as the stock class implementation of subref.

See the subsref help entry for more information about indexing and objects.

Changing the Portfolio Constructor

Object Precedence