I'm getting an error when I try to use parpool (MATLAB 2018a)

I'm trying to process some MRI data but the parpool function isn't working. I know there were some bugs in earlier versions of Matlab with macOS Sierra but this shouldn't be happening in the 2018a version?

Error using parpool (line 113) 'size' is not the name of a profile. Valid names are: 'local' 'MATLAB Parallel Cloud'

[Edric Ellis]

What precise command are you using to try and create the parallel pool?

[Agapi Dav]

Hi! I have exactly the same problem with matlab R2018a.

Error using parpool (line 113) 'size' is not the name of a profile. Valid names are: 'local' 'MATLAB Parallel Cloud'

I use this command:

if true
  % if(~parpool('size'))
  parpool
end
end

Can someone help me? Thanks in advance!

Answer 1

[Agapi Dav]

I think the problem is that the matlabpool was replaced by parpool. Therefore, matlabpool('size') is not valid anymore and parpool('size') does not do the job.

I found this quick fix here: https://github.com/RobotLocomotion/drake/issues/1009

try
  if (matlabpool('size')==0) matlabpool; end
catch
  if isempty(gcp('nocreate')) parpool; end
end

For me it worked. Cheers!

P.S. Thanks Ben, new here!

[Srishty Aggarwal]

when I use the command, I got the following error

Error using parpool (line 146)

Parallel pool failed to start with the following error. For more detailed information, validate the profile 'local'

in the Cluster Profile Manager.

Caused by:

Error using parallel.internal.pool.AbstractInteractiveClient>iThrowWithCause (line 305)

Failed to initialize the interactive session.

Error using parallel.internal.pool.AbstractInteractiveClient>iThrowIfBadParallelJobStatus (line 426)

The interactive communicating job failed with no message.

How to resolve it?

Answer 2

[Ben]

If you look at the parpool docs I don't believe you're using a valid input with

parpool('size')

as the error says, and you actually want to use

parpool(2)          %or whatever number of workers you want

Unless you want to make a non-local parpool. What are you trying to do?

[Agapi Dav]

Hi! I was testing a working function that I found on Internet and I wanted to implement on my code.

Good thing is that when I rebooted the PC everything worked without changing anything. Bad news, I have no idea why it works.

Thank you very much anyway.

[Agapi Dav]

So, I had changed something, I forgot. I think the problem was that the matlabpool was replaced by parpool. Therefore, matlabpool('size') is not valid anymore and parpool('size') (as I was trying) does not do the job.

I found this quick fix here: https://github.com/RobotLocomotion/drake/issues/1009

try
  if (matlabpool('size')==0) matlabpool; end
catch
  if isempty(gcp('nocreate')) parpool; end
end

For me it worked. Cheers!

[Ben]

Yeah, I see that matlabpool was removed in 2015a. If you don't need to support releases before 2015a, you don't need to use a try … catch and can just use parpool by itself (well, the if statement).

Also, you should write your solution in a new answer and accept it so that others with the same problem can see it :)