MATLAB: Does MATLAB copy large input parameters or does it operate on pointers

copylarge input parameterspointers

X is a large Array of matrices which is passed to a function f(X). Does MATLAB copy this Matrix or does the function f(X) read the original Matrix by means of pointers?

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Matlab takes a copy of a matrix only when you make a change to that matrix, so even though it does not use pass by reference (except for handle-derived classes) it will not take a copy of an array if you pass it to another function and use it for read-only purposes. The copy will happen when you make a change to the array in your function. i.e. essentially it uses copy-on-write semantics.

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You need to save a copy of the original in order to print it afterwards.

MATLAB: How to copy a Simulink Parameter Object by value in Simulink

In order to create a new Simulink Parameter Object from an existing one, use the "copy" method when using MATLAB R2012a or later.

The following code creates a copy by value of a Simulink Parameter object.

a=Simulink.Parameter; % create a parameter object
a.Value=5; % set a value
b=a.copy; % use copy
b.Value=10; % change the value in the copy
% Now we notice that the original value has not changed:
a.value

If you are using MATLAB versions prior to R2012a, please use "deepCopy" rather than "copy".

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