Thank you - it is refreshing to have a helpful answer. I am glad some people remember the days when they were first learning too.
On Thu, May 12, 2011 at 4:58 PM, jlemaitre [via R] < ml-node+3518836-766936252-236...@n4.nabble.com> wrote: > Nielsen, > The numbers in the brackets reference a component of a matrix/data > frame/vector. So if you have: > > x <- c(1:10) # a vector of integers in sequence from 1-10 > > x[3] # the third component of x > [1] 3 > > For 2-way matrices or data frames, the formatting is [row,column]. So, for > a 10 x 10 matrix x: > > x <- matrix(1:100, ncol = 10, byrow = T) > > x > [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] > [1,] 1 2 3 4 5 6 7 8 9 10 > [2,] 11 12 13 14 15 16 17 18 19 20 > [3,] 21 22 23 24 25 26 27 28 29 30 > [4,] 31 32 33 34 35 36 37 38 39 40 > [5,] 41 42 43 44 45 46 47 48 49 50 > [6,] 51 52 53 54 55 56 57 58 59 60 > [7,] 61 62 63 64 65 66 67 68 69 70 > [8,] 71 72 73 74 75 76 77 78 79 80 > [9,] 81 82 83 84 85 86 87 88 89 90 > [10,] 91 92 93 94 95 96 97 98 99 100 > > > x[,1] # return the first column of x > [1] 1 11 21 31 41 51 61 71 81 91 > > > x[1,] # return the first row of x > [1] 1 2 3 4 5 6 7 8 9 10 > > when there's a minus, it just means that component is omitted > > > x[-1,] # return x less the first row > [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] > [1,] 11 12 13 14 15 16 17 18 19 20 > [2,] 21 22 23 24 25 26 27 28 29 30 > [3,] 31 32 33 34 35 36 37 38 39 40 > [4,] 41 42 43 44 45 46 47 48 49 50 > [5,] 51 52 53 54 55 56 57 58 59 60 > [6,] 61 62 63 64 65 66 67 68 69 70 > [7,] 71 72 73 74 75 76 77 78 79 80 > [8,] 81 82 83 84 85 86 87 88 89 90 > [9,] 91 92 93 94 95 96 97 98 99 100 > > Given this context, I would double check the contents of test vs. test1. > And don't let arrogant posts on this help forum discourage you. > I hope this helps. > > > ------------------------------ > If you reply to this email, your message will be added to the discussion > below: > http://r.789695.n4.nabble.com/Row-names-and-matrixs-tp3516372p3518836.html > To unsubscribe from Row names and matrixs, click > here<http://r.789695.n4.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=3516372&code=bGluZHNleW5pZWxzZW5wY0BnbWFpbC5jb218MzUxNjM3MnwtMTcxNzE2OTY3OA==>. > > -- Lindsey Nielsen, Ph.D. Los Alamos National Lab (505) 667-2835 -- View this message in context: http://r.789695.n4.nabble.com/Row-names-and-matrixs-tp3516372p3524671.html Sent from the R help mailing list archive at Nabble.com. [[alternative HTML version deleted]] ______________________________________________ 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.
