I have a data frame that looks like this:
#df
ID DRUG FED AUC0t Tmax Cmax
1 1 0 100 5 20
2 1 1 200 6 25
3 0 1 NA 2 30
4 0 0 150 6 65
Ans so on. I want to summarize some statistics on AUC, Tmax and Cmax by drug DRUG and FED STATUS FED. I use dplyr. For example: for the AUC:
CI90lo <- function(x) quantile(x, probs=0.05, na.rm=TRUE)
CI90hi <- function(x) quantile(x, probs=0.95, na.rm=TRUE)
summary <- df %>%
group_by(DRUG,FED) %>%
summarize(mean=mean(AUC0t, na.rm=TRUE),
low = CI90lo(AUC0t),
high= CI90hi(AUC0t),
min=min(AUC0t, na.rm=TRUE),
max=max(AUC0t,na.rm=TRUE),
sd= sd(AUC0t, na.rm=TRUE))
However, the output is not grouped by DRUG and FED. It gives only one line containing the statistics of all by not faceted on DRUG and FED.
Any idea why? and how can I make it do the right thing?
I believe you've loaded plyr after dplyr, which is why you are getting an overall summary instead of a grouped summary.
This is what happens with plyr loaded last.
library(dplyr)
library(plyr)
df %>%
group_by(DRUG,FED) %>%
summarize(mean=mean(AUC0t, na.rm=TRUE),
low = CI90lo(AUC0t),
high= CI90hi(AUC0t),
min=min(AUC0t, na.rm=TRUE),
max=max(AUC0t,na.rm=TRUE),
sd= sd(AUC0t, na.rm=TRUE))
mean low high min max sd
1 150 105 195 100 200 50
Now remove plyr and try again and you get the grouped summary.
detach(package:plyr)
df %>%
group_by(DRUG,FED) %>%
summarize(mean=mean(AUC0t, na.rm=TRUE),
low = CI90lo(AUC0t),
high= CI90hi(AUC0t),
min=min(AUC0t, na.rm=TRUE),
max=max(AUC0t,na.rm=TRUE),
sd= sd(AUC0t, na.rm=TRUE))
Source: local data frame [4 x 8]
Groups: DRUG
DRUG FED mean low high min max sd
1 0 0 150 150 150 150 150 NaN
2 0 1 NaN NA NA NA NA NaN
3 1 0 100 100 100 100 100 NaN
4 1 1 200 200 200 200 200 NaN