Edric Ellis

Last seen: Today

MathWorks

821 total contributions since 2011

Developer at MathWorks, working on Parallel Computing Toolbox. Professional Interests: parallel computing, distributed arrays, gpu

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Answered
User defined functions with dynamic parameterisation in a parfor loops
This documentation for parfor notes various limitations - and also notes explicitly that you can create anonymous functions insi...

8 hours ago | 1

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Answered
In parfor-loop, can I call a multi-threaded mex and get some speed-up?
You should be able to run a multi-threaded MEX file correctly inside a parfor loop. However, you will be oversubscribing your ma...

14 days ago | 0

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Answered
Parallel computing, occasionally get Exception message "Message Catalog MATLAB:load was not loaded from the file"
The probable cause of this is the file handle limit. This page: https://www.mathworks.com/help/parallel-computing/recommended-sy...

1 month ago | 0

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Answered
How can I run parallel job on a specific node?
Based on this stackexchange answer https://unix.stackexchange.com/questions/443438/how-to-submit-a-job-to-a-specific-node-using-...

1 month ago | 0

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Answered
Are temporary variables eliminated at the end of each parfor loop on every single worker?
Yes, as mentioned in the documentation https://www.mathworks.com/help/parallel-computing/temporary-variable.html temporary varia...

1 month ago | 0

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Answered
Help with parfor progress bar using data queue
The problem here is that the documentation example is using a nested function, which is able to acces variables in the containin...

2 months ago | 1

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Answered
warning messages when using parfor in appdesigner app
It looks like you're either implicitly or explicitly using ASI within your parfor loop. You don't show the problematic code, but...

2 months ago | 0

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Answered
Distributing individual tasks over my pool of workers, scaling should be perfect
There are several confounding factors here that go some way at least to explaining your timings. In your first example (the fo...

2 months ago | 0

Answered
Problem using parfor for reading variable sized chunks of data into a larger pre-allocated container
There's no simple way to do this without at least some duplication of data. With some duplication of data, you could do somethin...

3 months ago | 0

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Answered
MATLAB NVIDIA Ampere GPU Support
See this answer: https://www.mathworks.com/matlabcentral/answers/592198-does-matlab-support-nvidia-ampere-cards-for-gpu-computat...

4 months ago | 0

Answered
"unable to classify the variable in the body of the parfor-loop"
The doc page you mention describes the valid ways of getting results out of a parfor loop. In your case, you appear to be comput...

6 months ago | 0

Answered
cplex object params not transferred to parfor loop
The most likely cause of the problem here is that the output of Cplex cannot be saved to a file and then loaded again. Transfer ...

6 months ago | 0

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Answered
Variable in parfor cannot be classified, error not shown in editor
The code you've shown there isn't complete enough for us to attempt to run and see the error you're encountering. It would be he...

6 months ago | 1

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Answered
parallel loop in matlab
Output variables in parfor loops must be either sliced outputs or reduction outputs. More info here in the doc. In this case, yo...

6 months ago | 0

Answered
MATLAB parfor index exceeds the number of array elements
To run a parfor loop, MATLAB analyses each variable used within the loop and classifies them. In the original code, non_crack_by...

6 months ago | 1

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Answered
how can i use pcg with Parallel Computing Toolbox ?
Simply: this problem is far too small for distributed arrays to be effective. You should use distributed arrays only for problem...

6 months ago | 1

Answered
The Tag Field of labSendReceive() Function
The function labSendReceive requires matched communication, so the receiver always knows which lab sent the data. In your exampl...

6 months ago | 0

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Answered
An Issue with SPMD
I think the problem here is the transformation of data types from outside spmd to inside. If you create a variable inside an spm...

6 months ago | 0

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Answered
Fast gpuArray slicing for cart2sph
Like all arrays in MATLAB, gpuArray data is stored in "column-major" order. One consequence of this is that it is much more effi...

6 months ago | 0

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Answered
parfor problems ( add attached files)
I think the problem here is that "fbt_.m" is a script file. You should convert it to a function. More in the doc about scripts a...

7 months ago | 0

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Answered
fetchNext idx always returning 1
The first output of fetchNext tells you which of the futures you passed in as an input has just completed. In your case, you are...

7 months ago | 1

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Answered
Why does performance of functions saturate with number of cores using parfeval but not with parfor?
The main difference between parfor and parfeval is that in the parfeval case, you are responsible for scheduling the work on the...

7 months ago | 0

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Answered
The variable newMap in a parfor cannot be classified.
This loop cannot run because the variable newMap is being read from and written to in arbitrary locations as the loop progresses...

7 months ago | 0

Answered
Progress bar with parfor and nohup
A really simple approach would be just to print out every 1000 iterations. In other words parfor i = 1:N if mod(i, 1000) =...

7 months ago | 0

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Answered
share data between workers while retrieving data from handle class within parpool
To get data out of a parfor loop, you must have either a "sliced output" or a "reduction output". Your code example above has ne...

7 months ago | 0

Answered
Restart a parpool worker
There's no simple way to do this when using parfor with parpool unfortunately. I can think of a couple of workarounds that might...

7 months ago | 0

Answered
How to use fetchNext correctly?
It looks like your seeder function depends only on the output of the corresponding call to partial_seeder. It might also be simp...

7 months ago | 0

Answered
How do I distribute N 3-dimensional (large) arrays for processing across N workers?
The best approach probably depends on the operations you need to perform on this Nx8xSxP array. Are the operations that you wish...

7 months ago | 0

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Answered
Is there any issue in using NVIDIA 1060 with MATLAB 2019?
The page detailing the GPUs supported by MATLAB is here. Also of relevance is NVIDIA's page decribing the CUDA capabilities of G...

7 months ago | 0

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Answered
How to speed up huge matrix mldivide?
distributed arrays on a single machine will generally perform worse than normal arrays - this is because the standard MATLAB mld...

7 months ago | 0

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