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Martin Wegmann

2004-Dec-14 11:23 UTC

[R] sort() leaves row names unaffected

Hello, 

I wonder if I ran into a bug. If I do 

summary(df1$X1) -> df1.y

df1.y
a  b   c   d  e
[1,] 50.74627 8.955224 17.91045 19.40299 2.985075

sort(df1.y) 
       a  b   c   d  e
[1,] 2.985075 8.955224 17.91045 19.40299 50.74627

my numbers are sorted but do not anymore correspond to the rownames. 
For me it is counterintuitive that solely the numbers are sorted and not the 
names. Is there a way to sort names + numbers or is this behaviour of sort() 
unintended?

Martin

R 2.0.1-1 debian reposit.

Uwe Ligges

2004-Dec-14 11:55 UTC

head link

[R] sort() leaves row names unaffected

Martin Wegmann wrote:
> Hello, 
> 
> I wonder if I ran into a bug. If I do 
> 
> summary(df1$X1) -> df1.y
> 
> df1.y
> a  b   c   d  e
> [1,] 50.74627 8.955224 17.91045 19.40299 2.985075
> 
> sort(df1.y) 
>        a  b   c   d  e
> [1,] 2.985075 8.955224 17.91045 19.40299 50.74627
Note: You are sorting a matrix rather than a vector!
> my numbers are sorted but do not anymore correspond to the rownames. 
You mean colnames, not rownames!
> For me it is counterintuitive that solely the numbers are sorted and not
the
> names. Is there a way to sort names + numbers or is this behaviour of
sort()
> unintended?
Don't use sort() on matrices, use order() instead, as in:

  x[,order(x)]

Uwe Ligges

> Martin
> 
> R 2.0.1-1 debian reposit.
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html

Petr Pikal

2004-Dec-14 12:17 UTC

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[R] sort() leaves row names unaffected

Hi

I am not sure how you did get such result of sort and summary

Summary usually gives
> summary(titr$kys)   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  0.000   1.050   1.250   1.143   1.369   2.000 

and sorting it
> y<-summary(titr$kys)
> y[1]<-5
> y[3]<-10
> y   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  5.000   1.050  10.000   1.143   1.369   2.000 > sort(y)1st Qu.    Mean 3rd Qu.    Max.    Min.  Median 
  1.050   1.143   1.369   2.000   5.000  10.000 

as well as
> x<-rnorm(5)*5
> names(x)<-letters[1:5]
> x         a          b          c          d          e 
-3.8849080  1.9393499  1.8456569 -2.5334288  0.6304933 > sort(x)         a          d          e          c          b 
-3.8849080 -2.5334288  0.6304933  1.8456569  1.9393499 


On 14 Dec 2004 at 12:23, Martin Wegmann wrote:

Didn't you redefine something?

Cheers
Petr

> Hello, 
> 
> I wonder if I ran into a bug. If I do 
> 
> summary(df1$X1) -> df1.y
> 
> df1.y
> a  b   c   d  e
> [1,] 50.74627 8.955224 17.91045 19.40299 2.985075
> 
> sort(df1.y) 
>        a  b   c   d  e
> [1,] 2.985075 8.955224 17.91045 19.40299 50.74627
> 
> my numbers are sorted but do not anymore correspond to the rownames.
> For me it is counterintuitive that solely the numbers are sorted and
> not the names. Is there a way to sort names + numbers or is this
> behaviour of sort() unintended?
> 
> Martin
> 
> R 2.0.1-1 debian reposit.
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
Petr Pikal
petr.pikal at precheza.cz

bogdan romocea

2004-Dec-14 13:30 UTC

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[R] sort() leaves row names unaffected

I asked the same question a few weeks ago. See
http://tolstoy.newcastle.edu.au/R/help/04/11/6775.html

-----Original Message-----
From: Martin Wegmann
Sent: Tuesday, December 14, 2004 6:23 AM
To: r-help at stat.math.ethz.ch
Subject: [R] sort() leaves row names unaffected

Hello, 

I wonder if I ran into a bug. If I do 

summary(df1$X1) -> df1.y

df1.y
a  b   c   d  e
[1,] 50.74627 8.955224 17.91045 19.40299 2.985075

sort(df1.y) 
       a  b   c   d  e
[1,] 2.985075 8.955224 17.91045 19.40299 50.74627

my numbers are sorted but do not anymore correspond to the rownames. 
For me it is counterintuitive that solely the numbers are sorted and
not the 
names. Is there a way to sort names + numbers or is this behaviour of
sort() 
unintended?

Martin

R 2.0.1-1 debian reposit.

______________________________________________
R-help at stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html

__________________________________ 

Dress up your holiday email, Hollywood style. Learn more.

Liaw, Andy

2004-Dec-14 13:33 UTC

head link

[R] sort() leaves row names unaffected

The problem, I think, boils down to the following:
> x <- matrix(c(3, 1, 2), ncol=3, dimnames=list(NULL, letters[1:3]))
> x     a b c
[1,] 3 1 2> sort(x)     a b c
[1,] 1 2 3> y <- rbind(x, c(1,1,2))
> y     a b c
[1,] 3 1 2
[2,] 1 1 2> sort(y)     a b c
[1,] 1 1 2
[2,] 1 2 3

I.e., I'm guessing your `df1.y' is a matrix with one row and column
names
`a' through `e'.  When you sort() a matrix, sort() simply treat it as a
vector (as a matrix in R is just a vector with a dim attribute) and sort
that (by stacking columns).  The output is sorted, but with the original
dimension and dimnames as the input.

Perhaps sort() should be made generic with methods for
matrix/array/data.frame, but one needs to think about what the logical thing
to do if no other argument is given...  In any case, it shouldn't give you
the result you're expecting (at least not by default): you are expecting the
result to be sorted columns, which hardly makes sense if there are more than
one row.

Andy
> From: Martin Wegmann
> 
> Hello, 
> 
> I wonder if I ran into a bug. If I do 
> 
> summary(df1$X1) -> df1.y
> 
> df1.y
> a  b   c   d  e
> [1,] 50.74627 8.955224 17.91045 19.40299 2.985075
> 
> sort(df1.y) 
>        a  b   c   d  e
> [1,] 2.985075 8.955224 17.91045 19.40299 50.74627
> 
> my numbers are sorted but do not anymore correspond to the rownames. 
> For me it is counterintuitive that solely the numbers are 
> sorted and not the 
> names. Is there a way to sort names + numbers or is this 
> behaviour of sort() 
> unintended?
> 
> Martin
> 
> R 2.0.1-1 debian reposit.
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! 
> http://www.R-project.org/posting-guide.html
> 
>

Liaw, Andy

2004-Dec-14 13:41 UTC

head link

[R] sort() leaves row names unaffected

I don't see how this is the `same' question at all.  The object Martin
has
doesn't look like a data frame (can you tell why?), so I believe is
unrelated to what you asked before.

Andy

ps: Why is this copied to debian_list at web.de?

> From: bogdan romocea
> 
> I asked the same question a few weeks ago. See
> http://tolstoy.newcastle.edu.au/R/help/04/11/6775.html
> 
> 
> -----Original Message-----
> From: Martin Wegmann
> Sent: Tuesday, December 14, 2004 6:23 AM
> To: r-help at stat.math.ethz.ch
> Subject: [R] sort() leaves row names unaffected
> 
> 
> Hello, 
> 
> I wonder if I ran into a bug. If I do 
> 
> summary(df1$X1) -> df1.y
> 
> df1.y
> a  b   c   d  e
> [1,] 50.74627 8.955224 17.91045 19.40299 2.985075
> 
> sort(df1.y) 
>        a  b   c   d  e
> [1,] 2.985075 8.955224 17.91045 19.40299 50.74627
> 
> my numbers are sorted but do not anymore correspond to the rownames. 
> For me it is counterintuitive that solely the numbers are sorted and
> not the 
> names. Is there a way to sort names + numbers or is this behaviour of
> sort() 
> unintended?
> 
> Martin
> 
> R 2.0.1-1 debian reposit.
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
> 
> 
> 
> 		
> __________________________________ 
> 
> Dress up your holiday email, Hollywood style. Learn more.
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! 
> http://www.R-project.org/posting-guide.html
> 
>

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