vector entry in matix
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hi,
i'm trying to figure out if there's any possibility to write a whole vector into a matrix or data.frame or something like that. i don't mean transormation. Here an example: [,1] [,2] [1,] "a" "d" [2,] "b" "e" [3,] "c" "f" where e.g. a is a<-c(0,1) vector of length 2, b a vector of length 4,... (i know that the matrix enties are strings :)). i'm trying to put some variables into a matrix or data.frame, but i couldn't handle it. is something like that possible in R? thanks for your help! |
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It is possible to put dimensionality on a list (i.e., a generic
vector), which might be what you're looking for. x <- list(1:4, letters[1:4], function(x,y) x + y, rnorm(50)) dim(x) <- c(2,2) x[[1,2]] x[[2,2]] x[[3,2]] # Error Best, Michael On Thu, Jul 5, 2012 at 8:19 AM, Thomas C. <[hidden email]> wrote: > hi, > > i'm trying to figure out if there's any possibility to write a whole vector > into a matrix or data.frame or something like that. i don't mean > transormation. Here an example: > > [,1] [,2] > [1,] "a" "d" > [2,] "b" "e" > [3,] "c" "f" > > > where e.g. a is a<-c(0,1) vector of length 2, b a vector of length 4,... (i > know that the matrix enties are strings :)). i'm trying to put some > variables into a matrix or data.frame, but i couldn't handle it. is > something like that possible in R? > > thanks for your help! > > -- > View this message in context: http://r.789695.n4.nabble.com/vector-entry-in-matix-tp4635478.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > [hidden email] 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. ______________________________________________ [hidden email] 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. |
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well thank you, i think we get closer to my problem. but i meant it in a different way. maybe i describe what i intended to do:
i have number of triangles which i'd like to store in a list, matrix,...etc. i thought it could look sth. like that: triangle node1 node2 node3 ..... 1 c(x1,y1) c(x2,y3) c(x3,y3) 1 c(x4,y4) c(x5,y5) c(x6,y6) . . . i know that i could just make more rows for the x/y values but the problem is, that i need to store more than these properties (say the neighbours of these nodes and their coordinates) and i thought it would be more convenient to save these as vectors. it was just a thought... is this possible? |
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In reply to this post by Thomas C.
Hi,
I think it is better to store vectors in to list when the vectors are of different lengths. #Consider these cases, #vectors of equal length set.seed(1) list1<-list(a=rnorm(5,15),b=rnorm(5,25),c=1:5,d=runif(5,0.4),e=16:20,f=rep(1,5)) mat1<-cbind(rbind(list1[[1]],list1[[2]],list1[[3]]),(rbind(list1[[4]],list1[[5]],list1[[6]]))) mat1 [,1] [,2] [,3] [,4] [,5] [,6] [,7] [1,] 16.43302 16.98040 14.63278 13.95587 15.56972 0.5371949 0.7574272 [2,] 24.86495 27.40162 24.96076 25.68974 25.02800 16.0000000 17.0000000 [3,] 1.00000 2.00000 3.00000 4.00000 5.00000 1.0000000 1.0000000 [,8] [,9] [,10] [1,] 0.7449233 0.4462386 0.4213243 [2,] 18.0000000 19.0000000 20.0000000 [3,] 1.0000000 1.0000000 1.0000000 dat1<-data.frame(list1) dat1 a b c d e f 1 16.43302 24.86495 1 0.5371949 16 1 2 16.98040 27.40162 2 0.7574272 17 1 3 14.63278 24.96076 3 0.7449233 18 1 4 13.95587 25.68974 4 0.4462386 19 1 5 15.56972 25.02800 5 0.4213243 20 1 #vectors of uneual length #works with list list2<-list(a=rnorm(5,15),b=rnorm(10,25),c=5:15,d=runif(3,0.4),e=1:5,f=rep(1:3,3)) > list2 $a [1] 15.36594 15.24841 15.06529 15.01916 15.25734 $b [1] 24.35099 24.88083 25.66414 26.10097 25.14377 24.88225 24.08793 23.56241 [9] 24.20291 26.25408 $c [1] 5 6 7 8 9 10 11 12 13 14 15 $d [1] 0.8679909 0.9283714 0.6478745 $e [1] 1 2 3 4 5 $f [1] 1 2 3 1 2 3 1 2 3 #Warning or Errors in matrix and dataframe mat2<-cbind(rbind(list2[[1]],list2[[2]],list2[[3]]),(rbind(list2[[4]],list2[[5]],list2[[6]]))) Warning messages: 1: In rbind(list2[[1]], list2[[2]], list2[[3]]) : number of columns of result is not a multiple of vector length (arg 1) 2: In rbind(list2[[4]], list2[[5]], list2[[6]]) : number of columns of result is not a multiple of vector length (arg 2) dat2<-data.frame(list2) Error in data.frame(a = c(15.3659411230492, 15.2484126488726, 15.0652881816716, : arguments imply differing number of rows: 5, 10, 11, 3, 9 #So, it would be better to store it as a list. #But, you can still convert vectors of unequal lengths to data frame or matrix with NAs. library(zoo) a<-zoo(1:8,1:14) b<-zoo(5:8,3:5) c<-zoo(1:5,2:5) list3<-list("a","b","c") z<-zoo() for(i in 1:length(list3)) z<-merge(z,get(list3[[i]])) names(z)<-unlist(list3) z a b c 1 1 NA NA 2 2 NA 1 3 3 5 2 4 4 6 3 5 5 7 4 6 6 NA NA 7 7 NA NA 8 8 NA NA 9 1 NA NA 10 2 NA NA 11 3 NA NA 12 4 NA NA 13 5 NA NA 14 6 NA NA z1<-data.frame(z) is.data.frame(z1) [1] TRUE str(z1) 'data.frame': 14 obs. of 3 variables: $ a: int 1 2 3 4 5 6 7 8 1 2 ... $ b: int NA NA 5 6 7 NA NA NA NA NA ... $ c: int NA 1 2 3 4 NA NA NA NA NA ... z2<-as.matrix(z) A.K. ----- Original Message ----- From: Thomas C. <[hidden email]> To: [hidden email] Cc: Sent: Thursday, July 5, 2012 9:19 AM Subject: [R] vector entry in matix hi, i'm trying to figure out if there's any possibility to write a whole vector into a matrix or data.frame or something like that. i don't mean transormation. Here an example: [,1] [,2] [1,] "a" "d" [2,] "b" "e" [3,] "c" "f" where e.g. a is a<-c(0,1) vector of length 2, b a vector of length 4,... (i know that the matrix enties are strings :)). i'm trying to put some variables into a matrix or data.frame, but i couldn't handle it. is something like that possible in R? thanks for your help! -- View this message in context: http://r.789695.n4.nabble.com/vector-entry-in-matix-tp4635478.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ [hidden email] 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. ______________________________________________ [hidden email] 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. |
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In reply to this post by Michael Weylandt
On Jul 5, 2012, at 11:22 AM, R. Michael Weylandt wrote: > It is possible to put dimensionality on a list (i.e., a generic > vector), which might be what you're looking for. > > x <- list(1:4, letters[1:4], function(x,y) x + y, rnorm(50)) > dim(x) <- c(2,2) > > x[[1,2]] > > x[[2,2]] > > x[[3,2]] # Error That constructs a 2 x 2 matrix whose elements are lists: > x [,1] [,2] [1,] Integer,4 ? [2,] Character,4 Numeric,50 > is.matrix(x) [1] TRUE I suppose one could take that approach to constructing an Excel-mimic, since the functional element survives that passage: > x[1,2][[1]](3,4) [1] 7 > > Best, > Michael > > On Thu, Jul 5, 2012 at 8:19 AM, Thomas C. <[hidden email]> > wrote: >> hi, >> >> i'm trying to figure out if there's any possibility to write a >> whole vector >> into a matrix or data.frame or something like that. i don't mean >> transormation. Here an example: >> >> [,1] [,2] >> [1,] "a" "d" >> [2,] "b" "e" >> [3,] "c" "f" >> >> >> where e.g. a is a<-c(0,1) vector of length 2, b a vector of length >> 4,... (i >> know that the matrix enties are strings :)). i'm trying to put some >> variables into a matrix or data.frame, but i couldn't handle it. is >> something like that possible in R? The matrix classes objects loose their names, however. You will not have a,b, ... as handles in that matrix. You could create row and column names. >> >> thanks for your help! >> David Winsemius, MD West Hartford, CT ______________________________________________ [hidden email] 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. |
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In reply to this post by Thomas C.
You have failed to provide a complete, coherent description of what you
wish to do. In the absence of such a description, all suggestions are just guesses. You need to think carefully about what information you want to associate with each triangle and the appropriate data structure to use to do this. You might do well to talk with a computer scientist about this. An object-oriented framework seems like the natural approach. This also sounds like the sort of thing Bioconductor might already have, so search around there, perhaps posting on their Help list. -- Bert On Thu, Jul 5, 2012 at 9:37 AM, Thomas C. <[hidden email]> wrote: > well thank you, i think we get closer to my problem. but i meant it in a > different way. maybe i describe what i intended to do: > > i have number of triangles which i'd like to store in a list, > matrix,...etc. > i thought it could look sth. like that: > > triangle node1 node2 node3 ..... > 1 c(x1,y1) c(x2,y3) c(x3,y3) > 1 c(x4,y4) c(x5,y5) c(x6,y6) > . > . > . > > i know that i could just make more rows for the x/y values but the problem > is, that i need to store more than these properties (say the neighbours of > these nodes and their coordinates) and i thought it would be more > convenient > to save these as vectors. it was just a thought... is this possible? > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/vector-entry-in-matix-tp4635478p4635509.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > [hidden email] 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. > -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm [[alternative HTML version deleted]] ______________________________________________ [hidden email] 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. |
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In reply to this post by Thomas C.
To second Bert Gunter: you may get better answers if you give us a complete
description. On Thu, Jul 5, 2012 at 12:37 PM, Thomas C. <[hidden email]> wrote: > i have number of triangles which i'd like to store in a list, > matrix,...etc. > i thought it could look sth. like that: > > triangle node1 node2 node3 ..... > 1 c(x1,y1) c(x2,y3) c(x3,y3) > 1 c(x4,y4) c(x5,y5) c(x6,y6) > You already indicate that that's not the whole truth, but if it was you could consider one of two approaches: * Rather than a 2D array (also called "matrix") use a 3D array, with dimensions n.triangle x 3 x 2. * You could use a n.triangle x 3 matrix of complex numbers. That may look like a sneaky trick to put a vector into a matrix element, but some operations of planar geometry can written elegantly. E.g., distance between a and b is abs(a-b). It all depends on what you want to do. BTW, what do you consider a neighbor of a triangle? * * If you are working with a triangle mesh, it might be better to hold the vertices in a double matrix (n.vertex x 2) and represent the triangles as indices into it, i.e., as an integer matrix (n.triangle x 3). You may use more columns in either matrix to represent more attributes. If you find out you need columns of different types, consider a data frame. /Christian [[alternative HTML version deleted]] ______________________________________________ [hidden email] 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. |
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In reply to this post by Thomas C.
Hi Thomas,
This is non trivial to do, but if you will be working with this sort of data and are inclined to do some programming, you might consider creating a new class. S4 classes and methods are quite flexible, and you can allow them to lean on or inherit from existing classes such as matrices. For example, your class might consist of three lists and a data frame. The length of each list would be forced to be equal to the number of rows in the data frame. Each element of each list would support a length 2 numeric vector (or integer vector or whatever it is you need). THe lists then would hold nodes 1 - 3, and the data frame would hold other information. You can similarly write methods so that for your special class, d[1, 1] would return c(x1, y1), essentially you create a mix of lists and a matrix with all the necessary constraints, and you develop methods that allow you to operate on this in a way that is sensible for your data. This is stab in the dark, but if you happen to be dealing with social network style data, (triangles and neighbors make me think of that), you should investigate existing packages for that as they may already have their own classes/have a way they expect data to be structured. Off the top of my head, the package "sna" comes to mind as a starting place to look (though I am not personally very familiar with it). Cheers, Josh On Thu, Jul 5, 2012 at 9:37 AM, Thomas C. <[hidden email]> wrote: > well thank you, i think we get closer to my problem. but i meant it in a > different way. maybe i describe what i intended to do: > > i have number of triangles which i'd like to store in a list, matrix,...etc. > i thought it could look sth. like that: > > triangle node1 node2 node3 ..... > 1 c(x1,y1) c(x2,y3) c(x3,y3) > 1 c(x4,y4) c(x5,y5) c(x6,y6) > . > . > . > > i know that i could just make more rows for the x/y values but the problem > is, that i need to store more than these properties (say the neighbours of > these nodes and their coordinates) and i thought it would be more convenient > to save these as vectors. it was just a thought... is this possible? > > > > -- > View this message in context: http://r.789695.n4.nabble.com/vector-entry-in-matix-tp4635478p4635509.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > [hidden email] 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. -- Joshua Wiley Ph.D. Student, Health Psychology Programmer Analyst II, Statistical Consulting Group University of California, Los Angeles https://joshuawiley.com/ ______________________________________________ [hidden email] 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. |
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