Problem's variable used by workers

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Andrea Stevanato 2018-5-30

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/403284-problem-s-variable-used-by-workers

评论： Andrea Stevanato 2018-5-31

I'm seeing documentation of parfor loop and i'm reading that i can't use global and persistent variables in parfor loop, so how i can share a "problem's variable" between workers? In my code there is a parfor loop that call some function, in this function that call other function (etc, etc) i need to read a "problem's variable", how i can do it without global and without pass variable between all function call? For exemple:

parfor i = 1:size(...)
  var = function1()
end
function result = function1()
  var2 = function2()
end
function result = function2()
  global varsProblems;
  %something else
end

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Andrea Stevanato 2018-5-31

在 MATLAB Online 中打开

I got an error using parallel.pool.Constant. In the script i create a struct with parallel.pool.Constant value as follow:

globalVar = who('global');
for index = 1:size(globalVar,1)
  constant.(globalVar{index}) =  parallel.pool.Constant(eval(globalVar{index}));
end

The struct was created correclty but into parfor-loop, when i call function that use this variable i can't access to constant struct. The code is the follow:

mainScript.m
parfor i = 1:tot
  result = myFunction();
end
myFunction.m()
% some code here
var = otherFunction();
otherFunction.m
if ~isempty(getCurrentWorker)
  global numberOfWorkers;
  global numberOfTasks;
else
  numberOfWorkers = constant.numberOfWorkers.Value;
  numberOfTasks = constant.numberOfTasks.Value;
end
% some code here

The error that I receive is the follow: Undefined variable "constant" or class "constant.numberOfWorkers.Value".

Andrea Stevanato 2018-5-31

在 MATLAB Online 中打开

An UndefinedFunction error was thrown on the workers for 'costant'.  This may be because the file containing 
'costant' is not accessible on the workers.  Specify the required files for this parallel pool using the command:
addAttachedFiles(pool, ...).  See the documentation for parpool for more details.
   Undefined function or variable 'costant'.