On 2012-03-19 15:00, Jorge I Velez wrote:
Hi David,
Thank you for the reproducible example!
Try
do.call(rbind, auc_stress)
cortisol amylase
2 919.05 6834.80
3 728.25 24422.05
4 2106.00 25908.35
6 636.40 12209.75
7 1925.95 4749.25
do.call(rbind, auc_control)
cortisol amylase
2 604.90 2458.00
4 587.65 29954.55
6 493.60 13833.80
7 1211.00 4932.35
HTH,
Jorge.-
Or with the plyr package:
library(plyr)
ldply(auc_stress)
Peter Ehlers
On Mon, Mar 19, 2012 at 5:44 PM, David Perlman<> wrote:
I could do this in various hacky ways, but what's the right way?
I have a nice application of the by function, which does what I want. The
output looks like this:
auc_stress
lab.samples.stress$subid: 2
cortisol amylase
1 919.05 6834.8
---------------------------------------------------------------------------------------------------------------------------
lab.samples.stress$subid: 3
cortisol amylase
11 728.25 24422.05
etc.
What I want is a data frame roughly like this:
subid cortisol.auc amylase.auc
2 919.05 6834.8
3 728.25 24422.05
etc.
What is a nice way to make that happen?
Here is the code and data that I am using, which should run directly if
you copy and paste it:
sanity.check<-read.csv("
http://brainimaging.waisman.wisc.edu/~perlman/testdata.csv";, header=TRUE,
sep = ",")
lab.samples<- subset(sanity.check,Sample!='before bed'& Sample!='morning
after')
lab.samples$Sample<-factor(lab.samples$Sample)
lab.samples.stress<-subset(lab.samples,challenge=='stress')
lab.samples.control<-subset(lab.samples,challenge=='control')
auc_ground<- function(sub_df) {
print(sub_df)
auc<-sub_df[1,]*0
timedif<-c(60,10,10,10,10,10,10)
for (i in 1:(nrow(sub_df)-1) ) {
print(c(i,i+1))
#print(c(values[i],values[i+1]))
pair_area<-(sub_df[i,]+sub_df[i+1,])*timedif[i]/2
auc<-auc+pair_area
}
auc
}
auc_stress<-by(lab.samples.stress[c('cortisol','amylase')],
lab.samples.stress$subid, auc_ground, simplify=T)
auc_control<-by(lab.samples.control[c('cortisol','amylase')],
lab.samples.control$subid, auc_ground, simplify=T)
Thanks for your help!
P.S. sorry if this question has been answered before, it is nearly
impossible to get useful google results on search terms like "by"... too
common word...
-dave----------------------------------------------------------------------
A neuroscientist is at the video arcade, when someone makes him a $1000 bet
on Pac-Man. He smiles, gets out his screwdriver and takes apart the Pac-Man
game. Everyone says "What are you doing?" The neuroscientist says "Well,
since we all know that Pac-Man is based on electric signals traveling
through these circuits, obviously I can understand it better than the other
guy by going straight to the source!"
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
