Why is the built-in quantizer object in MATLAB 6.5 (R13) passed by reference and not by value?

The following code demonstrates how the quantizer object is passed by reference.

function BugDemo()

q = quantizer

Change(q)

q

function Change(Q)

Q.format = [1 0]

The results of this code shows that changes made to the quantizer object in the "Change" function alter it within the "BugDemo" function.

Answer 1

[MathWorks Support Team]

Although this is different behavior than that in previous versions, it is the expected behavior.

The following steps will simulate the R12 behavior within R13:

1. Create a copy of the object within 'BugDemo' before passing it:

function BugDemo()

q = quantizer

q2 = copyobj(q);

Change(q2)

q

function Change(Q)

Q.format = [1 0]

2. Create a copy of the object within 'Change' before altering it:

function BugDemo()

q = quantizer

Change(q)

q

function Change(Q)

Q2 = copyobj(Q);

Q2.format = [1 0]