[R] possible error in stem() function?

[Zibeli Aton]

And thanks, Sarah, using scale=2 got me the sort of plot I was looking for.  I agree the help is a bit thin on that function.

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On Mon, 8/29/16, Sarah Goslee <sarah.goslee at gmail.com> wrote:

 Subject: Re: [R] possible error in stem() function?

 Cc: "r-help" <r-help at r-project.org>
 Date: Monday, August 29, 2016, 4:11 PM

 The help isn't
 particularly helpful, but you need to play with the
 scale argument.
 The range of
 your first dataset is long enough that you're getting
 only even-numbered stems by default.


 Try these:

 x1 <-
 c(479,482,487,493,494,494,495,496,497,498,498,499,503,504,507,507,508,

 510,511,512,514,516,520,524,525,525,527,534,536,542,545,546,547,549,
              
    557,559,561,561,563,563,567,568,569,570,572,578,584)
 stem(x1, scale=1)
 summary(x1)
 stem(x1,
 scale=2)

 x2 <-
 c(479,482,487,493,494,494,495,496,497,498,498,499,503,504,507,507,508,

 510,511,512,514,516,520,524,525,525,527,534,536,542,545,546,547,549,
              
    557,559,561,561,563,563,567,568,569,570,572,578)
 stem(x2, scale=1)
 summary(x2)
 stem(x2,
 scale=2)



 On Mon, Aug 29, 2016 at 1:42 PM, Zibeli Aton
 via R-help
 <r-help at r-project.org>
 wrote:
 > Using R-3.3.1 on Linux I seem to
 sometimes get inaccurate stem-and-leaf plots using stem. 
 For example:
 >
 >> x
 <-
 c(479,482,487,493,494,494,495,496,497,498,498,499,503,504,507,507,508,
 > +             
    510,511,512,514,516,520,524,525,525,527,534,536,542,545,546,547,549,
 > +             
    557,559,561,561,563,563,567,568,569,570,572,578,584)
 >> stem(x)
 >
 >   The decimal point is 1
 digit(s) to the right of the |
 >
 >   46 | 9
 >   48 | 27344567889
 >   50 | 3477801246
 >   52 | 0455746
 >   54 | 2567979
 >   56 | 1133789028
 >   58 | 4
 >
 > This plot is
 inaccurate since there are no values 469, 483, 484, etc. in
 the data.
 >
 > If I
 remove one value from the input, then the result appears
 correct:
 >
 >> x
 <-
 c(479,482,487,493,494,494,495,496,497,498,498,499,503,504,507,507,508,
 > +             
    510,511,512,514,516,520,524,525,525,527,534,536,542,545,546,547,549,
 > +             
    557,559,561,561,563,563,567,568,569,570,572,578)
 >> stem(x)
 >
 >   The decimal point is 1
 digit(s) to the right of the |
 >
 >   47 | 9
 >   48 | 27
 >   49 | 344567889
 >   50 | 34778
 >   51 | 01246
 >   52 | 04557
 >   53 | 46
 >   54 | 25679
 >   55 | 79
 >   56 | 1133789
 >   57 | 028
 >
 > Is there a limit to
 the length of the input argument, a bug in the function, or
 something I'm missing?
 >
 > Thanks.
 >