A subset of my raw data looks like this:
--------------
"Grip" "Technique" "Baseline.integrated" "Task"
"Stroke..direction." "Engag" "Disen"
"PenDG" "PenUG" "PenDS"
"PenUS" "Duration"
-------------
"Tripod","Barrel","Integrated",7,"S70",230,510,270,510,781,1011,1011
"Tripod","Barrel","Integrated",7,"S71","na","na","na","na","na","na","na"
"Round","NonPrefHand","Baseline",0,"S00","na","na",110,250,380,520,520
"Round","NonPrefHand","Baseline",0,"S01","na","na",220,360,460,620,620
--------------
I computed some values (times) from the raw data
---------------
t_p1=PenDG
t_c1=PenUG-PenDG
t_p2=PenDS-PenUG
t_c2=PenUS-PenDS
---------------
And I put those times in a data frame called "times". For each of these
times, I want to subtract the average for "Baseline" trials from the average
for "Integrated" trials within the "Grip" and "Technique" factors. Call
these differences the true cost of mode selection.
> truecost <-
function(time){as.numeric(tapply(time,Baseline.integrated,mean,na.rm=T)[2]-tapply(time,Baseline.integrated,mean,na.rm=T)[1])}
To help explain what the truecost function does:
> tapply(t_p1,Baseline.integrated,mean,na.rm=T)
Baseline Integrated
212.8000 252.8402
> truecost(t_p1)
[1] 40.04021
Then I try to create a table of average truecost as a function of levels of
a factor. I think this is the same error with tapply and by.
> tapply(t_p1,list(Grip,Technique),truecost,na.rm=T)
Error in FUN(X[[1L]], ...) : unused argument(s) (na.rm = TRUE)
> by(times,list(Grip,Technique),truecost,na.rm=T)
Error in FUN(data[x, , drop = FALSE], ...) :
unused argument(s) (na.rm = TRUE)
Any ideas?
Thomas Levine!
[[alternative HTML version deleted]]
______________________________________________
R-help@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.
