Re: [R] Subtraction with aggregate

2016-07-28 Thread Jim Lemon
Hi Gang, This is one way: gangdat<-read.table(text="subject QMemotion yi s1 75.1017 neutral -75.928276 s2 -47.3512 neutral -178.295990 s3 -68.9016 neutral -134.753906 s1 17.2099 negative -104.168312 s2 -53.1114 negative -182.373474 s3 -33.0322 negative -137.

Re: [R] Subtraction with aggregate

2016-07-28 Thread jim holtman
One thing to watch out for are there always two samples (one of each type) for each subject? You had better sort by the emotion to make sure that when you do the difference, it is always with the data in the same order.Here is an example of some of these cases where they are ignored: > libra

Re: [R] Subtraction with aggregate

2016-07-28 Thread Gang Chen
Hi Jim and Jeff, Thanks for the quick help! Sorry I didn't state the question clearly: I want the difference between 'neutral' and 'negative' for each subject. And another person offered a solution for it: aggregate(cbind(QM, yi) ~ subject, data = mydata, FUN = diff) On Thu, Jul 28, 2016 at 4:

Re: [R] Subtraction with aggregate

2016-07-28 Thread Jeff Newmiller
What represents the difference when multiple values are present? sd? -- Sent from my phone. Please excuse my brevity. On July 28, 2016 1:40:16 PM PDT, Gang Chen wrote: >With the following data in data.frame: > >subject QMemotion yi > s1 75.1017 neutral -75.928276 > s2 -47.3512

Re: [R] Subtraction with aggregate

2016-07-28 Thread jim holtman
Not sure what you mean by "nice way", but here is a dplyr solution: > library(dplyr) > mydata <- read.table(text = "subject QMemotion yi +s1 75.1017 neutral -75.928276 +s2 -47.3512 neutral -178.295990 +s3 -68.9016 neutral -134.753906 +s1 17.2099 negative -10

[R] Subtraction with aggregate

2016-07-28 Thread Gang Chen
With the following data in data.frame: subject QMemotion yi s1 75.1017 neutral -75.928276 s2 -47.3512 neutral -178.295990 s3 -68.9016 neutral -134.753906 s1 17.2099 negative -104.168312 s2 -53.1114 negative -182.373474 s3 -33.0322 negative -137.420410 I can