Re: [R] omit empty cells in crosstab?
On Fri, 2009-04-24 at 13:12 -0700, sjaffe wrote: > small example: > > a<-c(1.1, 2.1, 9.1) > b<-cut(a,0:10) > c<-data.frame(b,b) > d<-table(c) > dim(d) > ##result: c(10, 10) > > But only 9 of the 100 cells are non-zero. > If there were 10 columns, the table have 10 dimensions each of length 10, so > have 10^10 elements, too much even to fit in memory Hi Steve In your only 3 cells > 0 > d b.1 b(0,1] (1,2] (2,3] (3,4] (4,5] (5,6] (6,7] (7,8] (8,9] (9,10] (0,1] 0 0 0 0 0 0 0 0 0 0 (1,2] 0 1 0 0 0 0 0 0 0 0 (2,3] 0 0 1 0 0 0 0 0 0 0 (3,4] 0 0 0 0 0 0 0 0 0 0 (4,5] 0 0 0 0 0 0 0 0 0 0 (5,6] 0 0 0 0 0 0 0 0 0 0 (6,7] 0 0 0 0 0 0 0 0 0 0 (7,8] 0 0 0 0 0 0 0 0 0 0 (8,9] 0 0 0 0 0 0 0 0 0 0 (9,10] 0 0 0 0 0 0 0 0 0 1 If you desire use simple code to find only cell>0 use this table(interaction(c,drop=T)) (1,2].(1,2] (2,3].(2,3] (9,10].(9,10] 1 1 1 -- Bernardo Rangel Tura, M.D,MPH,Ph.D National Institute of Cardiology Brazil __ R-help@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.
Re: [R] omit empty cells in crosstab?
On Fri, Apr 24, 2009 at 3:12 PM, sjaffe wrote: > > small example: > > a<-c(1.1, 2.1, 9.1) > b<-cut(a,0:10) > c<-data.frame(b,b) > d<-table(c) > dim(d) > ##result: c(10, 10) > > But only 9 of the 100 cells are non-zero. > If there were 10 columns, the table have 10 dimensions each of length 10, so > have 10^10 elements, too much even to fit in memory Here's one way with the plyr package: library(plyr) ddply(c, names(c), nrow) Find more about plyr at http://had.co.nz/plyr Hadley -- http://had.co.nz/ __ R-help@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.
Re: [R] omit empty cells in crosstab?
I think the easiest way to deal with this problem is to paste together the values, use table on those, and then unpaste (strsplit) them back. Using the 10 columns with 10 levels example: set.seed(25) x = as.data.frame(replicate(10,sample(1:10,12,replace=TRUE))) res = apply(x,1,paste,collapse=':') tt1 = as.data.frame(table(res)) vals = strsplit(as.character(tt1$res),":") answer = data.frame(do.call(rbind,vals),Freq=tt1$Freq) answer X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 Freq 1 10 8 3 3 5 9 9 6 5 21 21 1 3 6 2 7 7 7 1 101 32 6 6 8 9 7 2 8 6 31 42 7 1 2 2 4 3 4 3 21 53 5 2 3 6 3 4 7 6 71 64 1 9 10 2 9 6 1 4 11 74 2 5 8 2 2 1 4 6 31 84 8 4 8 2 9 2 3 4 11 95 10 3 10 1 2 1 9 7 101 10 7 5 9 6 6 5 2 5 7 21 11 7 6 4 4 8 3 8 8 10 61 12 9 2 6 2 8 7 5 4 2 11 - Phil Spector Statistical Computing Facility Department of Statistics UC Berkeley spec...@stat.berkeley.edu On Fri, 24 Apr 2009, sjaffe wrote: small example: a<-c(1.1, 2.1, 9.1) b<-cut(a,0:10) c<-data.frame(b,b) d<-table(c) dim(d) ##result: c(10, 10) But only 9 of the 100 cells are non-zero. If there were 10 columns, the table have 10 dimensions each of length 10, so have 10^10 elements, too much even to fit in memory Dieter Menne wrote: sjaffe riskspan.com> writes: I have data with many factors, each taking many values. However, only relatively few combinations appear in the data, ie have nonzero counts, in other words the resulting table is sparse. Say we have 10 factors each with 10 levels. The result of table() would exceed the memory space (on a 32bit machine). Is there any way to produce a table with empty cells omitted? (without first producing the whole table and then removing rows.) It would be easier if you had a reproducible base example, but I suggest to create ONE new factor of the pasted levels using unique(), and creating a table of these. Dieter __ R-help@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. -- View this message in context: http://www.nabble.com/omit-empty-cells-in-crosstab--tp2363p23224071.html Sent from the R help mailing list archive at Nabble.com. __ R-help@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. __ R-help@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.
Re: [R] omit empty cells in crosstab?
small example: a<-c(1.1, 2.1, 9.1) b<-cut(a,0:10) c<-data.frame(b,b) d<-table(c) dim(d) ##result: c(10, 10) But only 9 of the 100 cells are non-zero. If there were 10 columns, the table have 10 dimensions each of length 10, so have 10^10 elements, too much even to fit in memory Dieter Menne wrote: > > sjaffe riskspan.com> writes: > >> >> I have data with many factors, each taking many values. However, only >> relatively few combinations appear in the data, ie have nonzero counts, >> in >> other words the resulting table is sparse. Say we have 10 factors each >> with >> 10 levels. The result of table() would exceed the memory space (on a >> 32bit >> machine). Is there any way to produce a table with empty cells omitted? >> (without first producing the whole table and then removing rows.) > > It would be easier if you had a reproducible base example, but I > suggest to create ONE new factor of the pasted levels using unique(), > and creating a table of these. > > Dieter > > __ > R-help@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. > > -- View this message in context: http://www.nabble.com/omit-empty-cells-in-crosstab--tp2363p23224071.html Sent from the R help mailing list archive at Nabble.com. __ R-help@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.
Re: [R] omit empty cells in crosstab?
Dieter Menne wrote: sjaffe riskspan.com> writes: I have data with many factors, each taking many values. However, only relatively few combinations appear in the data, ie have nonzero counts, in other words the resulting table is sparse. Say we have 10 factors each with 10 levels. The result of table() would exceed the memory space (on a 32bit machine). Is there any way to produce a table with empty cells omitted? (without first producing the whole table and then removing rows.) It would be easier if you had a reproducible base example, but I suggest to create ONE new factor of the pasted levels using unique(), and creating a table of these. interaction(..., drop=TRUE) may be a neater way. -- O__ Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~ - (p.dalga...@biostat.ku.dk) FAX: (+45) 35327907 __ R-help@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.
Re: [R] omit empty cells in crosstab?
sjaffe riskspan.com> writes: > > I have data with many factors, each taking many values. However, only > relatively few combinations appear in the data, ie have nonzero counts, in > other words the resulting table is sparse. Say we have 10 factors each with > 10 levels. The result of table() would exceed the memory space (on a 32bit > machine). Is there any way to produce a table with empty cells omitted? > (without first producing the whole table and then removing rows.) It would be easier if you had a reproducible base example, but I suggest to create ONE new factor of the pasted levels using unique(), and creating a table of these. Dieter __ R-help@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.
Re: [R] omit empty cells in crosstab?
Hi Steve, The general answer is yes, but the specific will depend on your problem. Could you provide a small reproducible example to illustrate your problem? Hadley On Fri, Apr 24, 2009 at 1:19 PM, sjaffe wrote: > > Perhaps this is a common question but I haven't been able to find the answer. > > I have data with many factors, each taking many values. However, only > relatively few combinations appear in the data, ie have nonzero counts, in > other words the resulting table is sparse. Say we have 10 factors each with > 10 levels. The result of table() would exceed the memory space (on a 32bit > machine). Is there any way to produce a table with empty cells omitted? > (without first producing the whole table and then removing rows.) > > Thanks, > Steve > > -- > View this message in context: > http://www.nabble.com/omit-empty-cells-in-crosstab--tp2363p2363.html > Sent from the R help mailing list archive at Nabble.com. > > __ > R-help@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. > -- http://had.co.nz/ __ R-help@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.
