R function implementation
Before rewriting in C, especially if you are new at it, have you profiled (Rprof) your function to see the time is being spent? Are you using dataframe or matrices; there is a big speed different between them when accessing data. So profile your code, see where the time is spent and then decide what to do about it. Depending on your choice of data structures and algorithms, R can be very fast. So take some time, profile your code and provide a sample of the function so that we can see what you are trying to do and then maybe we would suggest other approaches. I have been using R/SPlus for a number of years, know C reasonably well, and have yet to write any function in C to improve the speed of R.
On Wed, Dec 7, 2011 at 7:02 PM, Diviya Smith <diviya.smith at gmail.com> wrote:
Hello there, I recently wrote some code to perform pairwise correlations between all samples in a large dataset. So we are talking about performing pairwise correlations between 400K vectors. Since R has a very rich library of functions, it was very easy to code this in R. However, R was probably not the best choice as it is super slow for this large job. So my plan is to recode it in C. I was wondering if it is possible to see the code between some of the functions. I am looking for the raw code for simple data handling functions such as split, cut, etc so that I can directly use those in C. I am fairly new to programming in C and so this will be a big help. Thanks for you help in advance. Diviya ? ? ? ?[[alternative HTML version deleted]]
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Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it.