variable's scope, persistent variables and timer !!!!

Question

Bolivar 2013-9-3

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/86296-variable-s-scope-persistent-variables-and-timer

Hello!

I want to access a persistent variable from within timer StopFcn callback function. The callback should delete the timer and empty the persitent variable. my code look like this:

function callerfunc()
persitent resp;
persistent hTimer;
if isempty(resp)
resp=0;
end
if isempty(hTimer)
    timeout=5;
  hTimer =timer('TimerFcn',@(h)fprintf(' %s callerfunc''s Timer is ran out ...'),'StartDelay',timeout); 
hTimer.StopFcn = {@calledfunc, hTimer,resp};
end
start(hTimer);
end
function calledfunc(htimer,hresp)
delete(htimer);
hresp=[];
end

both functions are in the same file. Actually the call of calledfunc is a call by value and not by reference. therefore the persistent variable resp in callerfunc remaain unchanged after StopFcn excecute.can someone help me??

thanks!

Bolivar

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Answer 1

Walter Roberson 2013-9-3

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https://ww2.mathworks.cn/matlabcentral/answers/86296-variable-s-scope-persistent-variables-and-timer#answer_95772

在 MATLAB Online 中打开

You cannot do that. Nest your second function instead of having it just sequential.

function callerfunc()
persitent resp;
persistent hTimer;
if isempty(resp)
resp=0;
end
if isempty(hTimer)
    timeout=5;
  hTimer =timer('TimerFcn',@(h)fprintf(' %s callerfunc''s Timer is ran out ...'),'StartDelay',timeout); 
hTimer.StopFcn = @calledfunc;
end
start(hTimer);
    function calledfunc(varargin)
      delete(htimer);
      resp=[];
    end
end