[R] [External] Re: Speeding up a loop

[Rui Barradas]

Hello,

Anyway, I've redid part of the function in order to accomodate 1. larger 
increments and 2. keep if equal or not. So, here's the complete version 
and forget my two previous mails.

to.keep <- function(x, increment = 1e4, keep.if.equal = FALSE){
     keep <- function(i, env){
         env$ires <- env$ires + 1
         if(env$ires > env$curr.rows){
             env$result <- rbind(env$result, matrix(nrow=increment, 
ncol=nc))
             env$curr.rows <- env$curr.rows + increment
         }
         env$result[env$ires, ] <- x[i, ]
     }

     x  <- as.matrix(x)
     a1 <- x[, 1]
     a2 <- x[, 2]
     a3 <- x[, 3]
     a4 <- x[, 4]
     nc <- ncol(x)

     e <- new.env()
     e$curr.rows <- increment
     e$result <- matrix(nrow=e$curr.rows, ncol=nc)
     e$ires <- 0
     if(keep.if.equal){
         for(i in seq_len(nrow(x))){
             yes <- a1[i] >= a1 | a2[i] >= a2 | a3[i] <= a3 | a4[i] >= a4
             if(all(yes[-i])) keep(i, e)
         }
     }else{
         for(i in seq_len(nrow(x))){
             no <- a1[i] <= a1 & a2[i] <= a2 & a3[i] >= a3 & a4[i] <= a4
             if(!any(no[-i])) keep(i, e)
         }
     }
     e$result[seq_len(e$ires), 1:nc]
}


I hope this finally settles it.

Rui Barradas

Em 23-07-2012 18:18, Reith, William [USA] escreveu:
> It looks like both ways produce the same result.
>
> -----Original Message-----
> From: Rui Barradas [mailto:ruipbarradas at sapo.pt]
> Sent: Monday, July 23, 2012 1:05 PM
> To: Reith, William [USA]
> Subject: Re: [External] Re: [R] Speeding up a loop
>
> Hello,
>
> But that's the negation of '<', so try to negate '<=', meaning, remove the equal signs. Sorry if I wasn't very clear.
>
> Rui Barradas
>
> Em 23-07-2012 17:44, Reith, William [USA] escreveu:
>> This is what I have for the yes for loop
>>
>> for(i in seq_len(nrow(x))){
>>       yes <- x[i, 1] >= a1 | x[i, 2] >= a2 | x[i, 3] <= a3 | x[i, 4]>= a4
>>       if(all(yes)) keep(i, e)
>>     }
>>
>> -----Original Message-----
>> From: Rui Barradas [mailto:ruipbarradas at sapo.pt]
>> Sent: Monday, July 23, 2012 12:14 PM
>> To: Reith, William [USA]
>> Cc: r-help
>> Subject: [External] Re: [R] Speeding up a loop
>>
>> Hello,
>>
>> I think this is a boundary issue. In your op you've said "less" not "less than or equal to".
>> Try using "<=" and ">=" to see what happens, I bet it solves it.
>>
>> Rui Barradas
>>
>> Em 23-07-2012 14:43, wwreith escreveu:
>>> 1.15           60	0.553555415         0.574892872
>>> 1.15	   60	0.563183983         0.564029359
>>>
>>> Shouldn't the function row out the second one, since it it higher in
>>> position 3 and lower in position 4 i.e. it should not all be yes?
>>>
>>>
>>>
>>>
>>>
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