From daniel.frey at switzerland.org  Sat Aug 16 01:40:45 2003
From: daniel.frey at switzerland.org (daniel.frey@switzerland.org)
Date: Sat Aug 16 00:40:20 2003
Subject: [Rd] xtabs to dataframe fails (PR#3754)
Message-ID: <200308152240.h7FMejJH027483@pubhealth.ku.dk>

Full_Name: Daniel Frey
Version: 1.7.1
OS: Windows 2000
Submission from: (NULL) (80.254.164.242)


Generating a data frame out of a xtabs result acts unusual. Take the following
sample to reproduce it:

    > a.a <- c("a","a","a","b","b")

    > a.b <- c("c","c","d","e","f")

    > a.df <- data.frame(list("A"=a.a,"B"=a.b))

    > a.x <- xtabs(~A+B,a.df)

    > a.x
       B
    A   c d e f
      a 2 1 0 0
      b 0 0 1 1

    > data.frame(a.x)
      A B Freq
    1 a c    2
    2 b c    0
    3 a d    1
    4 b d    0
    5 a e    0
    6 b e    1
    7 a f    0
    8 b f    1

I would expect something like a.x itself. Instead I have to give the exact
bounds, otherwise it doesn't convert properly:

    > data.frame(a.x[1:2,1:4])
      c d e f
    a 2 1 0 0
    b 0 0 1 1

I consider this a bug, as consistency of the handling breaks here.

Daniel Frey


[Rd] xtabs to dataframe fails (PR#3754)
daniel.frey@switzerland.org