transforming a data frame to matrix
On Feb 18, 2012, at 8:35 AM, Adel ESSAFI wrote:
with simpler expressions: if I have a dataframe A B C is it possible de transform it to a matrix where nrow(A) colomns, nrow(B) row and for each value of C, we put the corresponding value in the matrix.
Perhaps: xtabs(C ~ A + B, data=dfrm) There will be an implicit summation of C-values in the presence of duplicates. For the application of other functions, you would use tapply. This untested code might give you counts: with(dfrm, tapply(C, list(A, B), length)
David. > Regards > > > > Le 18 f?vrier 2012 13:57, Adel ESSAFI <adelessafi at gmail.com> a ?crit : > >> Hello I had not planned on answering this question, because the data was too ambiguous. You should learn to use dput when posting data with your questions. >> >>> orderulcount >> Group.1 Group.2 Group.3 x V5 >> 7 C L 0.0 30 C / L >> 19 C L 0.2 27 C / L >> 31 C L 0.4 15 C / L >> 43 C L 0.6 7 C / L >> 54 C L 0.8 2 C / L >> 10 C S 0.0 27 C / S >> 22 C S 0.2 10 C / S >> 34 C S 0.4 6 C / S >> 46 C S 0.6 1 C / S >> 1 D D 0.0 30 D / D >> 13 D D 0.2 30 D / D >> 25 D D 0.4 17 D / D >> 37 D D 0.6 9 D / D >> 49 D D 0.8 2 D / D >> 3 D F 0.0 30 D / F >> 15 D F 0.2 26 D / F >> 27 D F 0.4 13 D / F >> 39 D F 0.6 3 D / F >> 51 D F 0.8 3 D / F >> 5 D I 0.0 26 D / I >> 17 D I 0.2 7 D / I >> 29 D I 0.4 7 D / I >> 41 D I 0.6 1 D / I >> 53 D I 0.8 1 D / I >> 8 D L 0.0 30 D / L >> 20 D L 0.2 26 D / L >> 32 D L 0.4 14 D / L >> 44 D L 0.6 8 D / L >> 55 D L 0.8 2 D / L >> 11 D S 0.0 27 D / S >> 23 D S 0.2 8 D / S >> 35 D S 0.4 4 D / S >> 47 D S 0.6 1 D / S >> 2 I D 0.0 30 I / D >> 14 I D 0.2 30 I / D >> 26 I D 0.4 14 I / D >> 38 I D 0.6 9 I / D >> 50 I D 0.8 2 I / D >> 4 I F 0.0 30 I / F >> 16 I F 0.2 29 I / F >> 28 I F 0.4 16 I / F >> 40 I F 0.6 5 I / F >> 52 I F 0.8 2 I / F >> 6 I I 0.0 30 I / I >> 18 I I 0.2 17 I / I >> 30 I I 0.4 4 I / I >> 42 I I 0.6 1 I / I >> 9 I L 0.0 30 I / L >> 21 I L 0.2 27 I / L >> 33 I L 0.4 17 I / L >> 45 I L 0.6 8 I / L >> 56 I L 0.8 2 I / L >> 12 I S 0.0 28 I / S >> 24 I S 0.2 11 I / S >> 36 I S 0.4 6 I / S >> 48 I S 0.6 3 I / S >> >> I have a data frame formed by 5 colomns. How to transform this data >> frame >> to a matrix formed as follow: >> 1. the colomn 5 is the comumn (string) >> 2. the colomn 5 row >> 3. the data are the colomn x. >> >> I aim to draw barplot later using the matrix. >> >> Thanks for any help >> >> >> >> >> >> >> >> >> >> -- >> PhD candidate in Computer Science >> Address >> 3 avenue lamine, cit? ezzahra, Sousse 4000 >> Tunisia >> tel: +216 97 246 706 (+33640302046 jusqu'au 15/6) >> fax: +216 71 391 166 >> > > > > -- > PhD candidate in Computer Science > Address > 3 avenue lamine, cit? ezzahra, Sousse 4000 > Tunisia > tel: +216 97 246 706 (+33640302046 jusqu'au 15/6) > fax: +216 71 391 166 > > [[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