Groups   10 of 99+      julia-users › copy a local variable to all parallel workers 7 posts by 5 authors      Gabor    10 5 15   I would like to copy a local variable to all parallel workers.  I thought that the following code would do the job: local_var 123  everywhere var local_var   But I get the following error:  ERROR: On worker 2: UndefVarError: local_var not defined  in eval at sysimg-jl:14  in anonymous at multi-jl:1350  in anonymous at multi-jl:892  in run_work_thunk at multi-jl:645   inlined code  from multi-jl:892  in anonymous at task-jl:63  in remotecall_fetch at multi-jl:731  ...and 2 other exceptions.   in sync_end at task-jl:413  in anonymous at multi-jl:1361   I ask for your help. What is the simplest solution for this simple problem?     Jameson    10 5 15   despite your naming convention, it looks like  local_var  was a global. try wrapping it in a let block:  let local_var 123  everywhere var $local_var end      Seth    10 5 15   As a related aside, what's the significance of the  $  in front of  local_var ?      Gabor    10 5 15   Thank you very much for your help! Even better, your solution also works within functions. I am with Seth with his question.  Could you explain the significance of $ in front of  local_var  ?      Andre Bieler    10 31 15   I have a similar question about getting data to all workers. Consider the following code:  ''' addprocs 2  using pfuncs      everywhere function showData      show data  end     function pstep      sync begin     for p in workers            async begin             remotecall_fetch p, showData          end     end   end end   everywhere data   myid   pstep   '''  If I uncomment the part where the showData   function is defined, it works as expected. If I put the definition of showData   into the file pfuncs-jl and import it as in the example above, it does not work.  From the manual I figure   using DummyModule causes the module to be loaded on all processes; however, the module is brought into scope only on the one executing the statement.   addresses the problem, but does not help me solve it. I also tried the let block posted by Jameson.  How do I get the same behaviour as with the  everywhere function definition in the commented block but being able to use modules?  For completeness here is the pfuncs-jl module:  ''' module pfuncs   export showData  function showData      show data  end  end '''        Jonathan Malmaud    10 31 15   The method 'pfunc.showData' isn't able to see the variable `data`, which exists as a global variable in the worker's 'Main' module, not it's 'pfuncs' module.       Andre Bieler    11 1 15   Thanks for the clarification.  How do I make it available to pfunc.showData then?  without having to explicitly send it as an argument in the function call   The goal would be to have a large chunk of data having locally available to the workers which then can independently work on it and only send the computed results.  I cannot do shared arrays as the actual data will not be bit types   Thanks