How to parallelize single function in R?

Let’s learn how to parallelize single function in R. The most accurate or helpful solution is served by Stack Overflow.

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What is the easiest way to parallelize a vectorized function in R?

I have a very large list X and a vectorized function f. I want to calculate f(X), but this will take a long time if I do it with a single core. I have (access to) a 48-core server. What is the easiest way to parallelize the calculation of f(X)? The following is not the right answer: library(foreach) library(doMC) registerDoMC() foreach(x=X, .combine=c) %dopar% f(x) The above code will indeed parallelize the calculation of f(X), but it will do so by applying f separately to every element of X...

Answer:

Although this is an older question this might be interesting for everyone who stumbled upon this via...

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Ryan Thompson at Stack Overflow Mark as irrelevant Undo

Other solutions

How to parallelize PNG file creation with C++, libpng and OpenMP?

I am currently trying to implement a PNG encoder in C++ based on libpng that uses OpenMP to speed up the compression process. The tool is already able to generate PNG files from various image formats. I uploaded the complete source code to pastebin.com...

Answer:

This loop seems parallelizable in a straightforward way. I would try just putting   #pragma omp for...

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Nazım Dugan at Quora Mark as irrelevant Undo

In Inkscape, when I use the "Trace Bitmap" function, how can I avoid ending up with the outline of the image when I want to get a single line sketch of the image?

When I go to the trace the bitmap of an image, instead of getting a line drawing version of it, I get an inner and outer outline of the image. Is there a way to get a single line image without having to draw it myself?

Answer:

What Inkscape does is find the two edges of the bitmap line, whether it's a fine or wide area. If I...

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Michel Poisson at Quora Mark as irrelevant Undo

An odesk contractor appears to have added a script to my site.  I want to be fair, is there any way this is a mistake?

He was modifying an existing site.  The site he created caused several words on my page to appear hyperlinked and when you moused over a little advertising window appeared.  My site did NOT do this before.  I commented out a script that was not on the...

Answer:

data.htm is an entry point and run.js contains the actual code to add underlined ads as well as what...

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Deep Joy Majumdar at Quora Mark as irrelevant Undo

Write a function that returns an array as result

QUESTION: Hi, How can I write a function that it can return an array as result? because of most of programs that I have seen just returns a single value as result. Can you help me how i can do it? If I must use pointers, I'll be thankful if you give...

Answer:

Hello Amir. Sorry, there is no pretty answer to this question. When you allocate memory with new,...

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Miningco.com Mark as irrelevant Undo

How to modify the find function

I am pulling data in from a website and have to use the 'Find' (Ctrl + F) function to locate the cell that I want to report, however the actual cell that I am reporting is 5 cells below the cell that is identified from the Find function. What I am having...

Answer:

Dan, You can do this with the offset property the below code assumes we are searching the activesheet...

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Miningco.com Mark as irrelevant Undo

Return variable's value to a function

QUESTION: I'm contacting you again because I'm trying to understand how pass value between functions in vba. Sub main() i = 0 r = 4 c = 2 rtp = 9 ctp = 2 Call ThisWorkbook.copycells(r, c, rtp, ctp, i) ...... ...... End Sub Sub copycells(r, c, rtp...

Answer:

simba24d, The value for merged cells is in the first cell of the merged range msgbox Worksheets("...

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Miningco.com Mark as irrelevant Undo

How do you integrate the Hankel function: r*Hankel(r)?

Integral of r times by hankel function of first kind of zero order , from 0 to a , I use mathematica : Integrate[ r * HankelH1[0,r],{r,0,a}] and I get the result but I have to show it by hand  . thanks

Answer:

You have to show it by hand? That's a pain. The Hankel functions are a different basis for the Bessel...

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Jack Wimberley at Quora Mark as irrelevant Undo

How do I call a plugin function inside a PHP template for WP sites?

I am using a pagination plugin in my WP site. As pagination works, it  must be laid inside an index.php file, else it will not show the output.  But i wish to call the same function in a template file. I have the php  code but when I call that function...

Answer:

Just  a simple suggestion that instead of making multiple copies of same  function, why not create a...

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Rahul Balakrishna at Quora Mark as irrelevant Undo

How to explain callbacks in plain English? How are they different from calling one function from another function?

How to explain callbacks in plain English? How are they different from calling one function from another function taking some context from the calling function? How can their power be explained to a novice programmer?

Answer:

Simply calling one function is the case that the caller F knows some function G that it can call when...

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Yu Feng at Quora Mark as irrelevant Undo

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