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.
On 29/08/2016 1:42 PM, Zibeli Aton via R-help 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.There's a 479, and a 493, etc. Since you only have even numbered stems you get two decades of leaves on each line. The ones for the 460's would precede the ones for the 470's if there were any; you can see that does happen in that the 480's do precede the 490's. Duncan Murdoch> > 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. > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. >
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.
>