thr3ads.net - R help - [R] why order doesn't work? [Jul 2012]

If this information is useful, please help other people find it:
Share via:

cowboy

2012-Jul-27 20:22 UTC

[R] why order doesn't work?

hi all,
I want to get a cumsum according to the order of some variable.
However, it doesnt' work.
For example,
**********************
test<-data.frame(cbind(x=c(3,5,2,6,7),y=c(8,1,4,9,0)))
test[order(test$x),]$sumy<-cumsum(test[order(test$x),]$y)
**********************
R complians Warning message:
In `[<-.data.frame`(`*tmp*`, order(test$x), , value = list(x = c(2,  :
  provided 3 variables to replace 2 variables.

while the following
***********************
test$sumy<-cumsum(test[order(test$x),]$y)
******************
gives
  x y sumy
1 3 8    4
2 5 1   12
3 2 4   13
4 6 9   22
5 7 0   22

should it gives

  x y sumy
1 3 8    12
2 5 1   13
3 2 4   4
4 6 9   22
5 7 0   22

What am I missing here?
thanks,
Guang

William Dunlap

2012-Jul-27 20:47 UTC

head link

[R] why order doesn't work?

> test<-data.frame(cbind(x=c(3,5,2,6,7),y=c(8,1,4,9,0)))
> test[order(test$x),]$sumy<-cumsum(test[order(test$x),]$y)
is asking a bit too much of R.  If you add the line
   test$sumy <- numeric(nrow(test))
between those lines you get what you want.

Here are the details.  The nested replacement expression
    dataFrame[subscript, ]$component <- value
is treated as the sequence of expressions
    TMP <- dataFrame[subscript,]
    TMP$component <- value
    dataFrame[subscript, ] <- TMP
If dataFrame has no column named 'component' then the last
expression involves trying to replace some rows of the n-column
data.frame dataFrame by the contents of the (n+1)-column data.frame
TMP and R will not do that.

By the way, drop the cbind from
   data.frame(cbind(x=..., y=...))
and just use
   data.frame(x=..., y=...)
The cbind() slows things down, wastes memory, and can give
surprising results (when x and y have different classes).


Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at
r-project.org] On
> Behalf Of cowboy
> Sent: Friday, July 27, 2012 1:23 PM
> To: r-help at r-project.org
> Subject: [R] why order doesn't work?
> 
> hi all,
> I want to get a cumsum according to the order of some variable.
> However, it doesnt' work.
> For example,
> **********************
> test<-data.frame(cbind(x=c(3,5,2,6,7),y=c(8,1,4,9,0)))
> test[order(test$x),]$sumy<-cumsum(test[order(test$x),]$y)
> **********************
> R complians Warning message:
> In `[<-.data.frame`(`*tmp*`, order(test$x), , value = list(x = c(2,  :
>   provided 3 variables to replace 2 variables.
> 
> while the following
> ***********************
> test$sumy<-cumsum(test[order(test$x),]$y)
> ******************
> gives
>   x y sumy
> 1 3 8    4
> 2 5 1   12
> 3 2 4   13
> 4 6 9   22
> 5 7 0   22
> 
> should it gives
> 
>   x y sumy
> 1 3 8    12
> 2 5 1   13
> 3 2 4   4
> 4 6 9   22
> 5 7 0   22
> 
> What am I missing here?
> thanks,
> Guang
> 
> ______________________________________________
> R-help at r-project.org mailing list
> 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.

Berend Hasselman

2012-Jul-27 20:52 UTC

head link

[R] why order doesn't work?

cowboy wrote> 
> hi all,
> I want to get a cumsum according to the order of some variable.
> However, it doesnt' work.
> For example,
> **********************
> test<-data.frame(cbind(x=c(3,5,2,6,7),y=c(8,1,4,9,0)))
> test[order(test$x),]$sumy<-cumsum(test[order(test$x),]$y)
> **********************
> R complians Warning message:
> In `[<-.data.frame`(`*tmp*`, order(test$x), , value = list(x = c(2,  :
>   provided 3 variables to replace 2 variables.
> 
> while the following
> ***********************
> test$sumy<-cumsum(test[order(test$x),]$y)
> ******************
> gives
>   x y sumy
> 1 3 8    4
> 2 5 1   12
> 3 2 4   13
> 4 6 9   22
> 5 7 0   22
> 
> should it gives
> 
>   x y sumy
> 1 3 8    12
> 2 5 1   13
> 3 2 4   4
> 4 6 9   22
> 5 7 0   22
> 
> What am I missing here?
> 
order is working just fine.
Apparently one cannot create a new column in a data.frame with the $
notation.
This will work

test[order(test$x),"sumy"]<-cumsum(test[order(test$x),]$y)

Berend




--
View this message in context:
http://r.789695.n4.nabble.com/why-order-doesn-t-work-tp4638149p4638152.html
Sent from the R help mailing list archive at Nabble.com.

Bert Gunter

2012-Jul-27 20:54 UTC

head link

[R] why order doesn't work?

This has nothing to do with order(). The following also reproduces the behavior:
> test <- data.frame(x=letters[1:5],y = 1:5)
> test[1:5,]$z <- 11:15Warning message:
In `[<-.data.frame`(`*tmp*`, 1:5, , value = list(x = 1:5, y = 1:5,  :
  provided 3 variables to replace 2 variables> test  x y
1 a 1
2 b 2
3 c 3
4 d 4
5 e 5> test$z <- 11:15
> test  x y  z
1 a 1 11
2 b 2 12
3 c 3 13
4 d 4 14
5 e 5 15

I don't know what's going on here, but it appears that it has
something to do (again!) with the $ convenience syntax, which is best
avoided, it seems. Instead of the rather convoluted syntax of the
first statement, note that
> test <- data.frame(x=letters[1:5],y = 1:5)
> test[1:5,"z"] <- 11:15
> test  x y  z
1 a 1 11
2 b 2 12
3 c 3 13
4 d 4 14
5 e 5 15

... works fine.
Have you read "An Intro to R"  where indexing is discussed?  If not,
why not? If so, please follow it. It will help you avoid such
difficulties.

-- Bert

On Fri, Jul 27, 2012 at 1:22 PM, cowboy <dgecon at gmail.com>
wrote:> hi all,
> I want to get a cumsum according to the order of some variable.
> However, it doesnt' work.
> For example,
> **********************
> test<-data.frame(cbind(x=c(3,5,2,6,7),y=c(8,1,4,9,0)))
> test[order(test$x),]$sumy<-cumsum(test[order(test$x),]$y)
> **********************
> R complians Warning message:
> In `[<-.data.frame`(`*tmp*`, order(test$x), , value = list(x = c(2,  :
>   provided 3 variables to replace 2 variables.
>
> while the following
> ***********************
> test$sumy<-cumsum(test[order(test$x),]$y)
> ******************
> gives
>   x y sumy
> 1 3 8    4
> 2 5 1   12
> 3 2 4   13
> 4 6 9   22
> 5 7 0   22
>
> should it gives
>
>   x y sumy
> 1 3 8    12
> 2 5 1   13
> 3 2 4   4
> 4 6 9   22
> 5 7 0   22
>
> What am I missing here?
> thanks,
> Guang
>
> ______________________________________________
> R-help at r-project.org mailing list
> 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.


-- 

Bert Gunter
Genentech Nonclinical Biostatistics

Internal Contact Info:
Phone: 467-7374
Website:
http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm

arun

2012-Jul-27 21:04 UTC

head link

[R] why order doesn't work?

HI,

I guess you want to get the cumsum of y according to the order of x,
test1<-test[order(test$x),]
?test2<-within(test1,{cumsumy<-cumsum(y)})
?test2
#? x y cumsumy
#3 2 4?????? 4
#1 3 8????? 12
#2 5 1????? 13
#4 6 9????? 22
A#5 7 0????? 22
A.K.





----- Original Message -----
From: cowboy <dgecon at gmail.com>
To: r-help at r-project.org
Cc: 
Sent: Friday, July 27, 2012 4:22 PM
Subject: [R] why order doesn't work?

hi all,
I want to get a cumsum according to the order of some variable.
However, it doesnt' work.
For example,
**********************
test<-data.frame(cbind(x=c(3,5,2,6,7),y=c(8,1,4,9,0)))
test[order(test$x),]$sumy<-cumsum(test[order(test$x),]$y)
**********************
R complians Warning message:
In `[<-.data.frame`(`*tmp*`, order(test$x), , value = list(x = c(2,? :
? provided 3 variables to replace 2 variables.

while the following
***********************
test$sumy<-cumsum(test[order(test$x),]$y)
******************
gives
? x y sumy
1 3 8? ? 4
2 5 1?  12
3 2 4?  13
4 6 9?  22
5 7 0?  22

should it gives

? x y sumy
1 3 8? ? 12
2 5 1?  13
3 2 4?  4
4 6 9?  22
5 7 0?  22

What am I missing here?
thanks,
Guang

______________________________________________
R-help at r-project.org mailing list
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.

Reasonably Related Threads

Search for more reasonably related threads

R help - Jul 2012 - why order doesn't work?

[R] why order doesn't work?

[R] why order doesn't work?

[R] why order doesn't work?

[R] why order doesn't work?

[R] why order doesn't work?

Reasonably Related Threads