Edric Ellis

Last seen: Today

MathWorks

832 total contributions since 2011

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

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Answered
Problem with parfor loop
That error basically means a worker crashed while trying to run the parfor loop. You mention that x is large. If you are using t...

5 hours ago | 0

Answered
How to speed up simulink parallel simulation using parsim command inside a for loop
To see the benefit of parsim, you need to set up multiple SimulationInput instances ahead of time, and then make a single call t...

1 day ago | 0

Answered
Parfor Loop Error with Classification
I think you can adapt this to work with parfor, but it's going to be a little bit of a stretch. Your variable z_new can be consi...

3 days ago | 1

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Answered
Critical code section inside parfor
Further to Walter's response, the closest analogy in parfor is a reduction variable. These may appear to be updated by multiple ...

14 days ago | 0

Answered
Can I use parfor and CVX togther
I'm not familiar with the CVX toolbox. However, a lot of parfor problems can be remedied by pushing the body of the loop into a ...

16 days ago | 1

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Answered
How to set all one gpuArray in mex?
You basically have two options: either create and uninitialized mxGPUArray and fill the values using CUDA code (either a kernel,...

16 days ago | 0

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Answered
How to check the Bytes of gpuArray?
Unfortunately, whos does not currently report the number of bytes used by a gpuArray on the GPU - the 4 bytes you see reported i...

17 days ago | 0

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Answered
Alternative ways to slice/manage data using PARFOR
parfor can work with struct and cell, but it's often a bit tricky because you need to satisfy the requirement that the slicing i...

21 days ago | 0

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Answered
Restart random numbers with parallel loop
The error that you're seeing there I think is because you've got an old version of your "State.mat" file - the error is the one...

28 days ago | 0

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Answered
Behaviour ofparfeval depends on debugging state (Bug?)
I suspect this is because when you don't stop in the debugger, the function can return as soon as F gets into state 'running', i...

1 month ago | 0

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Answered
Possible to speed up this gpuArray calculation with arrayfun() (or otherwise)?
A few points here. Firstly, (and most importantly), to time code on the GPU, you need to use either gputimeit, or you need to in...

1 month ago | 1

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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...

2 months 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...

2 months 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...

3 months 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-...

3 months 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...

3 months 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...

3 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...

3 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...

4 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...

4 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...

6 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...

7 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 ...

7 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...

7 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...

7 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...

7 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...

8 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...

8 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...

8 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...

8 months ago | 0

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