Re: [R] R help

The condition is true all the way until you index outside the vector... Cheers On 31 Mar 2018, 17.29 +0200, Henri Moolman , wrote: > Could you please provide help with something from R that I find rather > puzzling? In the small program below x[1]=1, . . . , x[5]=5. R

Re: [R] Parallel assignments and goto

mind is that people keep coming along and > sticking things into it." > -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) > > > On Tue, Feb 27, 2018 at 6:51 AM, Thomas Mailund <thomas.mail...@gmail.com> > > wrote: > > > Interestingly,

Re: [R] Parallel assignments and goto

76.3949 977.6235 1042.5035 2889.779   100       factorial_tr_manual(1000) 110.215 116.919  130.2337 118.7350  122.7495   255.062   100  factorial_tr_automatic_1(1000) 179.897 183.437  212.8879 187.8250  195.7670   979.352   100  factorial_tr_automatic_2(1000) 508.353 534.328  601.9643 560.7830  

Re: [R] Parallel assignments and goto

limit > llength_tr(make_llist(1000)) [1] 1000 I should be able to make the function go faster if I had a faster way of handling the variable assignments, but inside “with”, I’m not sure how to do that… Any suggestions? Cheers On 11 Feb 2018, 16.48 +0100, Thomas Mailund <thomas.mail...@gmai

Re: [R] Parallel assignments and goto

. It might be doable with JIT or something like that, but my goal is less ambitious. Using local, though, might be an approach. I will play around with that tomorrow. Cheers On 11 Feb 2018, 18.19 +0100, David Winsemius <dwinsem...@comcast.net>, wrote: > > > On Feb 11, 2018, at 7:48 AM,

[R] Parallel assignments and goto

Hi guys, I am working on some code for automatically translating recursive functions into looping functions to implemented tail-recursion optimisations. See https://github.com/mailund/tailr As a toy-example, consider the factorial function factorial <- function(n, acc = 1) { if (n <= 1)

Re: [R] define a list with names as variables

Do you mean like this? > f <- function(foo, bar) { + result <- list(bar) + names(result) <- foo + result + } > (x <- f("hello", "world")) $hello [1] "world" > names(x) [1] "hello" -- Thomas Mailund On 4 August 2017 at

Re: [R] ggplot2 geom_bar arrangement

The order the bars are plotted in is determined by the levels in a factor, and your labels are treated as a factor. You can make sure you keep the order of your labels by simply doing this: Lab <- factor(Lab, levels = Lab) before constructing the data frame. Cheers On 27 Jun 2017, 20.43

Re: [R] Delayed evaluation / lazy expression evaluation

and persistent data structures to implement queues  http://www.westpoint.edu/eecs/SiteAssets/SitePages/Faculty%20Publication%20Documents/Okasaki/jfp95queue.pdf Cheers On 24 Apr 2017, 16.35 +0200, Thomas Mailund <thomas.mail...@gmail.com>, wrote: > Hi, I’m playing around with ways of

Re: [R] asking for help

If you write something like indices <- rep(1:(163863/6069), each = 6069) you can get the i’th block of rows with table[indices == i,] It looks like a little more work than a loop would be since you have to run through all rows for each block, but the implicit loop in this approach is likely

[R] Delayed evaluation / lazy expression evaluation

Hi, I’m playing around with ways of implementing lazy evaluation of expressions. In R, function arguments are evaluated as promises but expressions are evaluated immediately, so I am trying to wrap expressions in thunks—functions with no arguments that evaluate an expression—to get something

Re: [R] Peformance question

f slow. It is why everybody yells 'vectorize' and 'use lapply' > all the time. Then again, I'm guessing because I dont understand your code:) > > Good luck, > PJ > > > > > On Apr 11, 2017 7:44 PM, "Thomas Mailund" <thomas.mail...@gmail.com > (mailto:t

[R] Peformance question

Hi y’all, I’m working on a book on how to implement functional data structures in R, and in particular on a chapter on implementing queues. You get get the current version here https://www.dropbox.com/s/9c2yk3a67p1ypmr/book.pdf?dl=0 and the relevant pages are 50-59. I’ve implemented three

Re: [R] Assessing the name of an object within an argument

10, 2017 4:04 AM, "Thomas Mailund" <mail...@birc.au.dk<mailto:mail...@birc.au.dk>> wrote: You can get that using `formals()`. my_func <- function(dataset = iris) { #print(dataset) # here I do not want to print the dataset but the name # of the object - iris in this

Re: [R] Assessing the name of an object within an argument

  You can get that using `formals()`. my_func <- function(dataset = iris) {   #print(dataset) # here I do not want to print the dataset but the name   # of the object - iris in this case - instead   print(formals()$dataset) # this is what you want } This gives you what the arguments were

Re: [R] Please help me, I'm trying to update my version of R

of packages, since the ones you have installed for version 3.2 R won't be available in the 3.3 installation, but *those* packages you can install using install.packages. Cheers -- Thomas Mailund On 22 August 2016 at 22:17:50, KMNanus (kmna...@gmail.com<mailto:kmna...@gmail.com>) wrote

Re: [R] optimize the filling of a diagonal matrix (two for loops)

  The nested for-loops could very easily be moved to Rcpp which should speed them up. Using apply functions instead of for-loops will not make it faster; they still have to do the same looping. At least, when I use `outer` to replace the loop I get roughly the same speed for the two versions

Re: [R] get() within function

  Hi Ivan, ls() inside a function gives you the variables in the local scope. If you want to get the variables defined in the global scope you need to tell ls() that. Check the difference between these three functions: > foo <- function() ls() > foo() Returns character(0) because there are no

Re: [R] Continuation-parsing / trampoline / infinite recursion problem

say to that :) Cheers Thomas On 11 August 2016 at 23:05:29, Duncan Murdoch (murdoch.dun...@gmail.com<mailto:murdoch.dun...@gmail.com>) wrote: On 10/08/2016 1:28 PM, Duncan Murdoch wrote: > On 10/08/2016 1:10 PM, Thomas Mailund wrote: >> That did the trick! >> >> I wa

Re: [R] Continuation-parsing / trampoline / infinite recursion problem

10/08/2016 2:39 PM, Thomas Mailund wrote: Ok, I think maybe I am beginning to see what is going wrong... Explicitly remembering the thunk parameters in a list works fine, as far as I can see. make_thunk <- function(f, ...) { remembered <- list(...) function(...) do.call(f, as.lis

Re: [R] Continuation-parsing / trampoline / infinite recursion problem

ct? Now why I can still get it to work when I call `cat` remains a mystery… Cheers Thomas On 10 August 2016 at 19:12:41, Thomas Mailund (mail...@birc.au.dk(mailto:mail...@birc.au.dk)) wrote: > > That did the trick! > > I was so focused on not evaluating the continuati

Re: [R] Continuation-parsing / trampoline / infinite recursion problem

  Well, they stay at 3 when I call cat (except for the final step going down in they recursion where `identity` is called, where they are 4). They do that both when I evaluate ... in the `make_thunk` function and when I don’t. But then, when I call `cat` it also worked before. I cannot keep

Re: [R] Continuation-parsing / trampoline / infinite recursion problem

> On 10/08/2016 1:10 PM, Thomas Mailund wrote: > > That did the trick! > > > > I was so focused on not evaluating the continuation that I completely > > forgot that the thunk could hold an unevaluated value… now it seems to be > > working for all the

Re: [R] Continuation-parsing / trampoline / infinite recursion problem

On 10 Aug 2016, at 19:15, Bert Gunter > wrote: make_thunk is probably unnecessary and apparently problematic. I think you could use do.call() instead, as do.call(f,list(...)) . Yes, make_thunk <- function(f, ...) function() do.call(f,

Re: [R] Continuation-parsing / trampoline / infinite recursion problem

But wait, how is it actually changing? And how did calling `cat` make the problem go away? Ok, I will go think about it… Thanks anyway, it seems to do the trick. > On 10 Aug 2016, at 19:10, Thomas Mailund <mail...@birc.au.dk> wrote: > > > That did the trick! >

Re: [R] Continuation-parsing / trampoline / infinite recursion problem

* the forced evaluation is necessary there, but I will figure that out when my tired brain has had a little rest. Thanks a lot! Thomas > On 10 Aug 2016, at 19:04, Duncan Murdoch <murdoch.dun...@gmail.com> wrote: > > On 10/08/2016 12:53 PM, Thomas Mailund wrote: >> &g

Re: [R] Continuation-parsing / trampoline / infinite recursion problem

ut the text inside it. Removing the `cat` line and I get the recursion error… Cheers Thomas > On 10 Aug 2016, at 18:53, Thomas Mailund <mail...@birc.au.dk> wrote: > > >> On 10 Aug 2016, at 13:56, Thomas Mailund <mail...@birc.au.dk> wrote: >> >

Re: [R] Continuation-parsing / trampoline / infinite recursion problem

> On 10 Aug 2016, at 13:56, Thomas Mailund <mail...@birc.au.dk> wrote: > > make_thunk <- function(f, ...) f(...) Doh! It is of course this one: make_thunk <- function(f, ...) function() f(…) It just binds a function call into a thunk so I can delay its evaluation.

Re: [R] Continuation-parsing / trampoline / infinite recursion problem

  Oh, I see that the make_thunk function is missing in my example. It is just this one make_thunk <- function(f, ...) f(...) On 9 August 2016 at 21:57:05, Thomas Mailund (mail...@birc.au.dk(mailto:mail...@birc.au.dk)) wrote: > [I’m really sorry if you receive this mail twice.

[R] Continuation-parsing / trampoline / infinite recursion problem

[I’m really sorry if you receive this mail twice. I just noticed I had sent it from a different account that the one I signed up to the mailing list on and I don’t know if that means it will be filtered; at least I haven’t received it myself yet.] I am playing around with continuation-passing