Re: [R] Odp: Programming: loop versus vector oriented

2010-09-20 Thread Petr PIKAL
Hi Jan Jan private napsal dne 18.09.2010 12:12:29: > Hello Petr, > > thank you for your ideas. The split() looks most realistic. > > What about this idea: > > 1. Define three functions Refun1, Refun2, Refun3 for the three different > sections of the calculations (same as you suggested) > 2.

Re: [R] Odp: Programming: loop versus vector oriented

2010-09-20 Thread Petr PIKAL
Hi Jan r-help-boun...@r-project.org napsal dne 17.09.2010 12:43:40: > Hello Petr, > > > but I think this is how your code really works. Did you try it? > > it does, but the R documentation says somewhere: > "Warning: for() loops are used in R code much less often than in > compiled languages. C

Re: [R] Odp: Programming: loop versus vector oriented

2010-09-18 Thread Jan private
Hello Petr, thank you for your ideas. The split() looks most realistic. What about this idea: 1. Define three functions Refun1, Refun2, Refun3 for the three different sections of the calculations (same as you suggested) 2. lambda = (Re <= 2320) * Refun1(Re) + ((Re > 2320) && (Re < 65 * dk)) *

Re: [R] Odp: Programming: loop versus vector oriented

2010-09-17 Thread Jan private
Hello Petr, > but I think this is how your code really works. Did you try it? it does, but the R documentation says somewhere: "Warning: for() loops are used in R code much less often than in compiled languages. Code that takes a `whole object' view is likely to be both clearer and faster in R."

Re: [R] Odp: Programming: loop versus vector oriented

2010-09-17 Thread Petr PIKAL
Hi Jan Jan private napsal dne 17.09.2010 12:43:40: > Hello Petr, > > > but I think this is how your code really works. Did you try it? > > it does, but the R documentation says somewhere: > "Warning: for() loops are used in R code much less often than in > compiled languages. Code that takes a

Re: [R] Odp: Programming: loop versus vector oriented

2010-09-16 Thread Petr PIKAL
Hi Jan but I think this is how your code really works. Did you try it? Regards Petr Jan private napsal dne 16.09.2010 13:22:05: > Hello Petr, > > > If you want to get results of your function for a vector of reynolds and > > dk you can use function outer and probably get rid of for cycle in

Re: [R] Odp: Programming: loop versus vector oriented

2010-09-16 Thread Jan private
Hello Petr, > If you want to get results of your function for a vector of reynolds and > dk you can use function outer and probably get rid of for cycle in the > function. > > outer(c(100, 530,2410), c(10, 150,200),lambda_wall) > [,1] [,2] [,3] > [1,] 0.640 0.6400