Edric Ellis

Last seen: 5 Tage ago

MathWorks

813 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 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...

7 Tage 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...

etwa 2 Monate 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...

3 Monate 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 ...

3 Monate 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...

3 Monate 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...

3 Monate 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...

3 Monate 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...

3 Monate 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...

3 Monate 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...

3 Monate 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...

3 Monate 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...

4 Monate 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...

4 Monate 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...

4 Monate 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...

4 Monate 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) =...

4 Monate ago | 0

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...

4 Monate 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...

4 Monate 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...

5 Monate 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...

5 Monate 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...

5 Monate 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...

5 Monate ago | 0

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Answered
How to fix my code with parfor-Loops array?
Output variables in parfor must be either sliced or reduction. There's more information in the doc. But basically, you cannot as...

5 Monate ago | 0

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Answered
UndefinedFunction error was thrown on the workers for 'filedata'
I'm a little confused by your example code there - I think there must be more going on. In your code, the piece spmd imgda...

5 Monate ago | 0

Answered
Problem with running code on gpu
Your code is not standalone, so I couldn't try it. But the main point is that you need to vectorise your code. This will speed t...

5 Monate ago | 0

Answered
Confusing results when measuring time of function on CPU/GPU with tic-toc/(gpu)timeit
Ok, there's a lot going on here. A few observations: Putting scalar values on the GPU is often counter-productive, since the im...

5 Monate ago | 1

Answered
How to make sure that function is entirely run on GPU?
Operations on gpuArray data automatically take place on the GPU. When you operate on mixed GPU and CPU data, generally the opera...

5 Monate ago | 1

Answered
Memory Parfor Needs more memory than normal
When you transfer data to the workers for a parfor loop, there is a transient increase in memory over and above what you'd expec...

5 Monate ago | 1

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Answered
parfor doesn't continue to run other jobs when only one worker is working
parfor sends loop iterations to workers in groups known as "subranges" for efficiency. Also, recent versions of Parallel Computi...

5 Monate ago | 0

Answered
Use system function with parfor
It looks like your executable expects to read from input.txt and write to output.txt. This will not work in parallel because the...

5 Monate ago | 1