RE: [R] Keeping factors with zero occurrences in "table" output

From: Liaw, Andy <andy_liaw_at_merck.com>
Date: Thu 21 Apr 2005 - 02:24:19 EST


If you make them into factors, the empty ones should show up:

> f1 <- sample(1:7, 10, replace=TRUE)
> f2 <- sample(1:6, 10, replace=TRUE)
> table(f1, f2)

   f2
f1 1 2 3 5 6
  1 0 0 1 0 0
  2 0 0 1 0 0
  3 0 0 2 1 0
  4 0 1 0 0 1
  5 1 1 0 0 0
  7 0 0 0 1 0
> ff1 <- factor(f1, levels=1:7)
> ff2 <- factor(f2, levels=1:7)
> table(ff1, ff2)

   ff2
ff1 1 2 3 4 5 6 7
  1 0 0 1 0 0 0 0
  2 0 0 1 0 0 0 0
  3 0 0 2 0 1 0 0
  4 0 1 0 0 0 1 0
  5 1 1 0 0 0 0 0
  6 0 0 0 0 0 0 0
  7 0 0 0 0 1 0 0

HTH,
Andy

> From: Ravi Varadhan
>
> Dear R group,
>
>
>
> I have a data frame which contains data on preferences on 7
> items (ranks 1
> through 7) listed by each participant. I would like to
> tabulate this in a
> 7x7 table where the rows would be the items and the columns
> would be the
> number of times that item received a particular rank.
>
>
>
> I tried doing this by creating a matrix by "rbind"ing each
> vector obtained
> using "table" on each item. This, however, does not work
> because there are
> some items which didn't receive some of the ranks, so "table"
> does not list
> that item. Is there a way to force it to list the item and
> give a "0" to
> it? Or, is there a simpler way to solve this problem?
>
>
>
> Thanks for any help,
>
> Ravi.
>
>
>
> --------------------------------------------------------------
> ------------
>
> Ravi Varadhan, Ph.D.
>
> Assistant Professor, The Center on Aging and Health
>
> Division of Geriatric Medicine and Gerontology
>
> Johns Hopkins University
>
> Ph: (410) 502-2619
>
> Fax: (410) 614-9625
>
> Email: <mailto:rvaradhan@jhmi.edu> rvaradhan@jhmi.edu
>
> --------------------------------------------------------------
> ------------
>
>
>
>
> [[alternative HTML version deleted]]
>
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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Thu Apr 21 03:48:40 2005

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