From berwin at maths.uwa.edu.au  Mon Nov 13 07:16:18 2006
From: berwin at maths.uwa.edu.au (Berwin A Turlach)
Date: Mon, 13 Nov 2006 14:16:18 +0800
Subject: [Rd] "stem" does not give a correct answer (PR#9359)
In-Reply-To: <20061113044011.61CB53D747@slim.kubism.ku.dk>
References: <20061113044011.61CB53D747@slim.kubism.ku.dk>
Message-ID: <17752.3506.647574.792102@bossiaea.maths.uwa.edu.au>

G' day Myung,

>>>>> "MGK" == mgkim  <mgkim at seowon.ac.kr> writes:

    MGK> For the data c1 of size 14, stem provides the following result.

    MGK> **************************************************************
    >> c1
    MGK> [1] 14 39 70 11 38 20 37 15 41 74 74 34 48 51
    ZZangi> stem(c1)

    MGK> The decimal point is 1 digit(s) to the right of the |

    MGK> 0 | 145
    MGK> 2 | 04789
    MGK> 4 | 181
    MGK> 6 | 044

    MGK> **************************************************************
    MGK> However, stem does not give a correct answer, for example 34, 74, etc.

No bug, it is just the scale to which stem decides to plot by
default.  The line 

        4 | 181

should give a clue that this summarises 41, 48 and 51.  Since the data
is so sparse only even leading numbers are used.  Try:

> dat <- c(14, 39, 70, 11, 38, 20, 37, 15, 41, 74, 74, 34, 48, 51)
> stem(dat)

  The decimal point is 1 digit(s) to the right of the |

  0 | 145
  2 | 04789
  4 | 181
  6 | 044

> stem(dat, scale=2)

  The decimal point is 1 digit(s) to the right of the |

  1 | 145
  2 | 0
  3 | 4789
  4 | 18
  5 | 1
  6 | 
  7 | 044

Cheers,

        Berwin

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[Rd] "stem" does not give a correct answer (PR#9359)
Berwin A Turlach