MATLAB Programming

9 Classes and Objects
overloaded methods with function calls rather than using operators like '()',
'{}', or'.'.
For example, suppose you define a polynomial class that defines a subsref
method that causes the polynomial to beevaluatedwiththevalueofthe
independent variable equal to the subscript. Therefore,
p = polynom([1 0 -2 -5]);
The following subscripted expression returns the value of the polynomial at
x = 3 and x = 4.
p([3 4])
ans =
16 51
Now suppose that you want to use this feature in one of the class methods. To
do so, you must call the subsref function directly:
y = polyval(p,x);
subs.type = '()';
subs.subs = {x};
y = subsref(p, subs);
% Need to call subsref here
Handling Subscripted Reference
The use of a subscript or field designator with an object on the right-hand side
of an assignment statement is known as a subscripted reference. MATLAB
calls a method named subsref in these situations.
Object subscripted references can be of three forms — an array index, a cell
array index, and a structure field name:
A(I)
A{I}
A.field
Each of these results in a call by MATLAB to the subsref method in the class
directory. MATLAB passes two arguments to subsref.
B = subsref(A,S)
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