How to pass a parameter by reference in Matlab
I am new to Matlab and am learning about the following question online and am having difficulty solving it. I have a 1 x 20 matrix called current_load
which I have to update periodically. This matrix is in the main Matlab workspace (as shown below in the code).
current_loads = zeros(1, 20);
for col=1:20
current_loads(1,col)=10; %// Initially give all nodes a current value of 10
end
Object = HandleObject(current_load);%To pass by reference
recursive_remove(Object, 0);
To pass current_load
by reference, I created the following HandleObject.m class
classdef HandleObject < handle
properties
Object=[];
end
methods
function obj=HandleObject(receivedObject)
obj.Object=receivedObject;
end
end
end
This matrix will be passed to the function call recursive_remove
(see below).
function recursive_remove( current_load, val )
current_load.object = new matrix;
if(val<10)
current_load.object(1,3) = 2+val; %Not the correct way of using current_load ??
end
recursive_remove( current_load, current_load.object (1,3) )
end
The intent here is to change the variable current_load
in this function and later I can see these same changes from the main one. But this code doesn't work as I don't know how to follow the link. I need to traverse the link since I am calling this recursively without going back to the main one to force it to overwrite its variable in the caller. Please provide an example if possible.
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If you really need this feature, you can take a look at turning your HandleObject class into a singleton like this:
classdef HandleObject < handle
properties
Object=[];
end
methods(Static)
function obj = Instance(receivedObject)
persistent uniqueInstance
try
if isempty(uniqueInstance)
obj = HandleObject(receivedObject);
uniqueInstance = obj;
else
obj = uniqueInstance;
end
catch ME
disp(ME.getReport);
end
end
end
methods
function obj=HandleObject(receivedObject)
obj.Object=receivedObject;
end
end
end
Your recursive function will get a little simpler:
function recursive_remove(val )
current_load = HandleObject.Instance();
current_load.object = new matrix;
if(val<10)
current_load.object(1,3) = 2+val;
end
recursive_remove(current_load.object (1,3) )
end
And to instantiate the HandleObject class do the following:
Object = HandleObject.Instance(current_load);
Hope this helps you further.
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