How to clear persistent variables?

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Daniel
Daniel 2013-12-5
评论： Shubham Baisthakur 2021-5-4
I am currently using a persistent variable within a function that I would like to clear at the end of the execution of a larger program. I am currently using "clear functions". This is causing some headaches during debugging since this clears my breakpoints as well. Is there a way to clear only the persistent variables? Better yet, is there a way to clear specific persistent variables?

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Yair Altman
Yair Altman 2013-12-5
编辑：Yair Altman 2013-12-5
you can use
clear functionName
and all the persistent vars in that function will be cleared (set to [])
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Alexander Ryan
Alexander Ryan 2019-4-27
So is there a way to clear persistent variables in local or nested functions?

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TADA
TADA 2019-4-27
编辑：TADA 2019-4-27
You can clear the name of the .m file in which that function is declared
it works for .m file functions, local functions, nested functions, class methods
it also works if you kept a function handle to that function
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Walter Roberson
Walter Roberson 2021-5-4
clear NAME
where NAME is the name of a file that contains the function with the persistent variable you want to clear, without file extension. For example
clear project17
for file project17.m
There is no way to clear selectively within a file.

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will wehner
will wehner 2014-1-8
%Example Function
function testCleanup
disp(' ')
k = 3;
myFun;
for i=1:2\n
myFun
end
function myFun
persistent x
if(isempty(x))
x=1;
disp('empty')
else
disp('not empty')
end
end
end %end testCleanup
The function myFun is called 3 times. Once, then 2 more times in a loop. When running this function for the first time it will display
empty
not empty
not empty
on each subsequent run of testCleanup, it displays
not empty
not empty
not empty
It is my desire to clear the persistent variable x at the end of the function testCleanup. Simply clearing the function does not work. Using the whos command outside the function scope does not work. Is there any way to use onCleanup to clear the persistent variable x?
  1 个评论
Image Analyst
Image Analyst 2014-1-8
Try this:
function testCleanup
clc;
k = 3;
myFun;
for i=1:2
myFun
end
clear functions;
function myFun
persistent x
if(isempty(x))
x=1;
disp('empty')
else
disp('not empty')
end
end
end %end testCleanup

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sixwwwwww
sixwwwwww 2013-12-5
you can use:
clear YourVariableName
see for more information:
http://www.mathworks.com/help/matlab/ref/clear.html
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sixwwwwww
sixwwwwww 2013-12-5
Maybe you can try the following commands:
Vars=whos;
PersistentVars=Vars([Vars.persistent]);
PersistentVarNames={PersistentVars.name};
clear(PersistentVarNames{:});

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morteza
morteza 2015-1-23
you can use each of these instructions: clear all or clear classes or clear functions
Viktor Svensson
Viktor Svensson 2016-6-27
Ran into this problem today, wanted to clear persistent variables and not the debug points. The best I could come up with was
debugStatus = dbstatus(fileName);
clear(fileName);
dbstop(debugStatus)
where dbstatus reads the debug points in the file and dbstop returns them after the clear.

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