MATLAB Object-Oriented Programming

• obj = p.method — Use dot notation to call methods without arguments and return a
  modified object.

subsref Implementation Details

The subsref method overloads the subsref function.

For example, consider a call to the polyval function:

p = DocPolynom([1 0 -2 -5])

p =

x^3 - 2*x - 5

polyval(p.coef,[3 5 7])

ans =

16 110 324

The polyval function requires the:

• Polynomial coefficients


• Values of the independent variable at which to evaluate the polynomial

The polyval function returns the value of f(x) at these values. subsref calls polyval

through the statements:

case '()'

ind = s.subs{:};

b = polyval(a.coef,ind);

When implementing subsref to support method calling with arguments using dot

notation, both the type and subs structure fields contain multiple elements.

The subsref method implements all subscripted reference explicitly, as show in the

following code listing.

methods

function b = subsref(a,s)

switch s(1).type

case '()'

ind = s.subs{:};

b = polyval(a.coef,ind);

case '.'

switch s(1).subs

case 'coef'

b = a.coef;

19 Defining Custom Data Types