Hi all,
I'm working on a loop function for a large dataset which contains 1000
different groups. I would like to reconstruct the order of events within
each group by using a loop function in R. (Currently the order of events are
based on the ascending order of prev_event within the group)
A demo data frame:
event prev_event group
845 0 5360
926 153 5360
993 234 5360
234 845 5360
848 926 5360
153 993 5360
234 0 8765
968 234 8765
545 968 8765
625 111 3334
744 181 3334
181 227 3334
713 625 3334
227 713 3334
913 0 2329
372 119 2329
719 189 2329
119 324 2329
761 355 2329
890 372 2329
266 719 2329
324 761 2329
189 890 2329
355 913 2329
Below is what I have written:
ordering <- vector("list", length(unique(mydata$group)))
for (j in 1:length(unique(mydata$group))){
group.j <- mydata[mydata$group == unique(mydata$group)[j], ]
ordering.j <- c()
ordering.j[1] <- ifelse(group.j[1, ]$prev_event == 0, group.j[1, ]$event,
group.j[1, ]$prev_event)
for (i in 2:nrow(group.j)){
ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i-1], ]$event}
ordering[j] <- ordering.j}
ordering
What I got is:
Error in ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i - :
replacement has length zero> ordering
[[1]]
NULL
[[2]]
NULL
[[3]]
NULL
However, when I accidentally put a typo in the loop function, instead of
ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i-1], ]$event},
I put
ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i-1],
]$prev_event},
The output is a list of 1000 entries, each with the first event within the
group, and I received the following warning messages:
[[1]]
[1] 1.000680e+17
[[2]]
[1] 1.001390e+17
[[3]]
[1] 1.001450e+17
49: In ordering[j] <- ordering.j :
number of items to replace is not a multiple of replacement length
50: In ordering.j[i] <- group.j[group.j$prev_event == ... :
number of items to replace is not a multiple of replacement length
Why is this happening, and how can I fix it? Any pointer will be greatly
appreciated!
[[alternative HTML version deleted]]
It's better to avoid loop in this situation. If you want to reorder
subsets of the data based on event, the follow works
df<-read.table('clipboard',header=TRUE)
sp.or<-lapply(split(df,df$group),function(ldf) ldf[order(ldf$event),])
new.df<-do.call('rbind',sp.or)
Weidong Gu
On Wed, Oct 12, 2011 at 10:55 AM, Sally Zhen <saliluna at gmail.com>
wrote:> Hi all,
>
> I'm working on a loop function for a large dataset which contains 1000
> different groups. I would like to reconstruct the order of events within
> each group by using a loop function in R. (Currently the order of events
are
> based on the ascending order of prev_event within the group)
>
>
> A demo data frame:
>
> event ? ? ? prev_event ? group
> 845 ? ? ? ? ?0 ? ? ? ? ? ? ? 5360
> 926 ? ? ? ? ?153 ? ? ? ? ? ?5360
> 993 ? ? ? ? ?234 ? ? ? ? ? ?5360
> 234 ? ? ? ? ?845 ? ? ? ? ? ?5360
> 848 ? ? ? ? ?926 ? ? ? ? ? ?5360
> 153 ? ? ? ? ?993 ? ? ? ? ? ?5360
> 234 ? ? ? ? ?0 ? ? ? ? ? ? ? 8765
> 968 ? ? ? ? ?234 ? ? ? ? ? ?8765
> 545 ? ? ? ? ?968 ? ? ? ? ? ?8765
> 625 ? ? ? ? ?111 ? ? ? ? ? ?3334
> 744 ? ? ? ? ?181 ? ? ? ? ? ?3334
> 181 ? ? ? ? ?227 ? ? ? ? ? ?3334
> 713 ? ? ? ? ?625 ? ? ? ? ? ?3334
> 227 ? ? ? ? ?713 ? ? ? ? ? ?3334
> 913 ? ? ? ? ?0 ? ? ? ? ? ? ? 2329
> 372 ? ? ? ? ?119 ? ? ? ? ? ?2329
> 719 ? ? ? ? ?189 ? ? ? ? ? ?2329
> 119 ? ? ? ? ?324 ? ? ? ? ? ?2329
> 761 ? ? ? ? ?355 ? ? ? ? ? ?2329
> 890 ? ? ? ? ?372 ? ? ? ? ? ?2329
> 266 ? ? ? ? ?719 ? ? ? ? ? ?2329
> 324 ? ? ? ? ?761 ? ? ? ? ? ?2329
> 189 ? ? ? ? ?890 ? ? ? ? ? ?2329
> 355 ? ? ? ? ?913 ? ? ? ? ? ?2329
>
>
> Below is what I have written:
>
> ordering <- vector("list", length(unique(mydata$group)))
> for (j in 1:length(unique(mydata$group))){
> group.j <- mydata[mydata$group == unique(mydata$group)[j], ]
> ordering.j <- c()
> ordering.j[1] <- ifelse(group.j[1, ]$prev_event == 0, group.j[1,
]$event,
> group.j[1, ]$prev_event)
> for (i in 2:nrow(group.j)){
> ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i-1], ]$event}
> ordering[j] <- ordering.j}
> ordering
>
> What I got is:
> Error in ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i -
?:
> ?replacement has length zero
>> ordering
> [[1]]
> NULL
>
> [[2]]
> NULL
>
> [[3]]
> NULL
>
>
> However, when I accidentally put a typo in the loop function, instead of
> ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i-1],
]$event},
> I put
> ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i-1],
> ]$prev_event},
> The output is a list of 1000 entries, each with the first event within the
> group, and I received the following warning messages:
> [[1]]
> [1] 1.000680e+17
>
> [[2]]
> [1] 1.001390e+17
>
> [[3]]
> [1] 1.001450e+17
>
> 49: In ordering[j] <- ordering.j :
> ?number of items to replace is not a multiple of replacement length
> 50: In ordering.j[i] <- group.j[group.j$prev_event == ?... :
> ?number of items to replace is not a multiple of replacement length
>
>
> Why is this happening, and how can I fix it? Any pointer will be greatly
> appreciated!
>
> ? ? ? ?[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
On Oct 12, 2011, at 10:55 AM, Sally Zhen wrote:> Hi all, > > I'm working on a loop function for a large dataset which contains 1000 > different groups. I would like to reconstruct the order of events > within > each group by using a loop function in R.Not generally a good first strategy in R.> (Currently the order of events are > based on the ascending order of prev_event within the group)Wouldn't this just be: dfrm[order(dfrm$group, dfrm$event), ] (Ascending is the default ordering.) -- David.> > > A demo data frame: > > event prev_event group > 845 0 5360 > 926 153 5360 > 993 234 5360 > 234 845 5360 > 848 926 5360 > 153 993 5360 > 234 0 8765 > 968 234 8765 > 545 968 8765 > 625 111 3334 > 744 181 3334 > 181 227 3334 > 713 625 3334 > 227 713 3334 > 913 0 2329 > 372 119 2329 > 719 189 2329 > 119 324 2329 > 761 355 2329 > 890 372 2329 > 266 719 2329 > 324 761 2329 > 189 890 2329 > 355 913 2329 > > > Below is what I have written: > > ordering <- vector("list", length(unique(mydata$group))) > for (j in 1:length(unique(mydata$group))){ > group.j <- mydata[mydata$group == unique(mydata$group)[j], ] > ordering.j <- c() > ordering.j[1] <- ifelse(group.j[1, ]$prev_event == 0, group.j[1, ] > $event, > group.j[1, ]$prev_event) > for (i in 2:nrow(group.j)){ > ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i-1], ] > $event} > ordering[j] <- ordering.j} > ordering > > What I got is: > Error in ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i > - : > replacement has length zero >> ordering > [[1]] > NULL > > [[2]] > NULL > > [[3]] > NULL > > > However, when I accidentally put a typo in the loop function, > instead of > ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i-1], ] > $event}, > I put > ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i-1], > ]$prev_event}, > The output is a list of 1000 entries, each with the first event > within the > group, and I received the following warning messages: > [[1]] > [1] 1.000680e+17 > > [[2]] > [1] 1.001390e+17 > > [[3]] > [1] 1.001450e+17 > > 49: In ordering[j] <- ordering.j : > number of items to replace is not a multiple of replacement length > 50: In ordering.j[i] <- group.j[group.j$prev_event == ... : > number of items to replace is not a multiple of replacement length > > > Why is this happening, and how can I fix it? Any pointer will be > greatly > appreciated! > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.David Winsemius, MD West Hartford, CT
Is this the result you are after, where the event number (within a group) are sorted according to the event/prev_event pairs (prev_event in a row matches event of the previous row)?> ave(d, d$group, FUN=function(z) z[ match(tsort(z$prev_event, z$event)[-1], z$event), ])event prev_event group 1 845 0 5360 2 234 845 5360 3 993 234 5360 4 153 993 5360 5 926 153 5360 6 848 926 5360 7 234 0 8765 8 968 234 8765 9 545 968 8765 10 625 111 3334 11 713 625 3334 12 227 713 3334 13 181 227 3334 14 744 181 3334 15 913 0 2329 16 355 913 2329 17 761 355 2329 18 324 761 2329 19 119 324 2329 20 372 119 2329 21 890 372 2329 22 189 890 2329 23 719 189 2329 24 266 719 2329 'tsort' is a topological sorting function, like the Unix tsort. It is overkill for this application (and probably could be faster and do some more error checking) but I had it hanging around: tsort <- function (before, after) { # topological sort: Kahn's 1962 algorithm, from Wikipedia # before and after should be equal-length vectors of the # same type. L <- before[0] S <- setdiff(before, after) while (length(S) > 0) { n <- S[1] S <- S[-1] L[length(L) + 1] <- n m <- after[e <- before == n] after <- after[!e] before <- before[!e] S <- c(S, m[!is.element(m, after)]) } if (length(after) > 0) { stop("Graph contains a cycle") } else { L } } Your data was d <- data.frame( event = c(845, 926, 993, 234, 848, 153, 234, 968, 545, 625, 744, 181, 713, 227, 913, 372, 719, 119, 761, 890, 266, 324, 189, 355), prev_event = c(0, 153, 234, 845, 926, 993, 0, 234, 968, 111, 181, 227, 625, 713, 0, 119, 189, 324, 355, 372, 719, 761, 890, 913), group = c(5360, 5360, 5360, 5360, 5360, 5360, 8765, 8765, 8765, 3334, 3334, 3334, 3334, 3334, 2329, 2329, 2329, 2329, 2329, 2329, 2329, 2329, 2329, 2329)) Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Sally Zhen > Sent: Wednesday, October 12, 2011 7:56 AM > To: r-help at r-project.org > Subject: [R] loop function within a loop > > Hi all, > > I'm working on a loop function for a large dataset which contains 1000 > different groups. I would like to reconstruct the order of events within > each group by using a loop function in R. (Currently the order of events are > based on the ascending order of prev_event within the group) > > > A demo data frame: > > event prev_event group > 845 0 5360 > 926 153 5360 > 993 234 5360 > 234 845 5360 > 848 926 5360 > 153 993 5360 > 234 0 8765 > 968 234 8765 > 545 968 8765 > 625 111 3334 > 744 181 3334 > 181 227 3334 > 713 625 3334 > 227 713 3334 > 913 0 2329 > 372 119 2329 > 719 189 2329 > 119 324 2329 > 761 355 2329 > 890 372 2329 > 266 719 2329 > 324 761 2329 > 189 890 2329 > 355 913 2329 > > > Below is what I have written: > > ordering <- vector("list", length(unique(mydata$group))) > for (j in 1:length(unique(mydata$group))){ > group.j <- mydata[mydata$group == unique(mydata$group)[j], ] > ordering.j <- c() > ordering.j[1] <- ifelse(group.j[1, ]$prev_event == 0, group.j[1, ]$event, > group.j[1, ]$prev_event) > for (i in 2:nrow(group.j)){ > ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i-1], ]$event} > ordering[j] <- ordering.j} > ordering > > What I got is: > Error in ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i - : > replacement has length zero > > ordering > [[1]] > NULL > > [[2]] > NULL > > [[3]] > NULL > > > However, when I accidentally put a typo in the loop function, instead of > ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i-1], ]$event}, > I put > ordering.j[i] <- group.j[group.j$prev_event == ordering.j[i-1], > ]$prev_event}, > The output is a list of 1000 entries, each with the first event within the > group, and I received the following warning messages: > [[1]] > [1] 1.000680e+17 > > [[2]] > [1] 1.001390e+17 > > [[3]] > [1] 1.001450e+17 > > 49: In ordering[j] <- ordering.j : > number of items to replace is not a multiple of replacement length > 50: In ordering.j[i] <- group.j[group.j$prev_event == ... : > number of items to replace is not a multiple of replacement length > > > Why is this happening, and how can I fix it? Any pointer will be greatly > appreciated! > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.