Re: [R] vectorisation

2013-02-03 Thread Berend Hasselman
On 02-02-2013, at 17:38, Brett Robinson brett.robin...@7dials.com wrote: Hi I'm trying to set up a simulation problem without resorting to (m)any loops. I want to set entries in a data frame of zeros ('starts' in the code below) to 1 at certain points and the points have been randomly

[R] vectorisation

2013-02-02 Thread Brett Robinson
Hi I'm trying to set up a simulation problem without resorting to (m)any loops. I want to set entries in a data frame of zeros ('starts' in the code below) to 1 at certain points and the points have been randomly generated and stored in a separate data.frame ('sl'), which has the same number of

Re: [R] vectorisation

2013-02-02 Thread arun
(starts1) identical(starts1,starts2) #[1] TRUE A.K. - Original Message - From: Brett Robinson brett.robin...@7dials.com To: r-help@r-project.org r-help@r-project.org Cc: Sent: Saturday, February 2, 2013 11:38 AM Subject: [R] vectorisation Hi I'm trying to set up a simulation problem

Re: [R] vectorisation

2013-02-02 Thread Rui Barradas
Hello, Try the following. set.seed(4315) ml - data.frame(matrix(sample(1:50,80, replace=TRUE),20,4)) mm - apply(ml, 2, cumsum) s2 - starts - data.frame(matrix(0,600,4)) for (i in 1:4){ starts[,i][mm[,i]] - 1 } s2[] - lapply(seq_len(ncol(mm)), function(i) {s2[,i][mm[,i]] - 1; s2[,i]})

Re: [R] vectorisation?

2010-07-26 Thread Dimitris Rizopoulos
have a look at function rollapply() from package zoo. I hope it helps. Best, Dimitris On 7/26/2010 8:28 AM, Raghu wrote: Hi I have 3500 rows of data (say a single column) in a vector. If I want to compare every ith element with the simple average of the previous (i-5) elements, then I could

[R] vectorisation?

2010-07-26 Thread Raghu
Hi I have 3500 rows of data (say a single column) in a vector. If I want to compare every ith element with the simple average of the previous (i-5) elements, then I could write something like this: for(i in 6:NROW(data)){ if(data[i] = mean(data[(i-5):i]) (counter[i]=1)} } Is it possible

Re: [R] vectorisation?

2010-07-26 Thread Raghu
Many thanks Dimitris. On Mon, Jul 26, 2010 at 9:13 AM, Dimitris Rizopoulos d.rizopou...@erasmusmc.nl wrote: have a look at function rollapply() from package zoo. I hope it helps. Best, Dimitris On 7/26/2010 8:28 AM, Raghu wrote: Hi I have 3500 rows of data (say a single column) in