On Mar 7, 2012, at 10:36 AM, Michael Karol wrote:
All:It now appears to be working; however, I have a new problem. The format of the output is not what I need. Currently it produces an output as three columns; "Group.1", "Group.2", and "x" whereas I need a data frame with columns of Day, Hour, mean, sd, median, min, max.
Just anme the categories in the by list and the function:
Interestingly, the output appears on the console looking like the data frame I need with 7 columns, but internally it only has 3.I'm using R version 2.14.0 (2011-10-31)Group.1 Group.2 x.1 x.2 x.3 x. 4 x.5 1 1 0.0 0.0003333333 0.0005773503 0.0000000000 0.0000000000 0.0010000000 2 8 0.0 0.0003333333 0.0005773503 0.0000000000 0.0000000000 0.0010000000MeansByDayTimesnipped
My example data set and script follows. # Create a Test Data Frame Subject <-c(1001,1001,1001,1001,1001,1001,1001,1001,1001, 1002,1002,1002,1002,1002,1002,1002,1002,1002, 1003,1003,1003,1003,1003,1003,1003,1003,1003, 1001,1001,1001,1001,1001,1001,1001,1001,1001, 1002,1002,1002,1002,1002,1002,1002,1002,1002, 1003,1003,1003,1003,1003,1003,1003,1003,1003 ) Day <- c (1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8 ) Hour <- c(0,0.5,1,2,2.5,3,4,6,12, 0,0.5,1,2,2.5,3,4,6,12, 0,0.5,1,2,2.5,3,4,6,12, 0,0.5,1,2,2.5,3,4,6,12, 0,0.5,1,2,2.5,3,4,6,12, 0,0.5,1,2,2.5,3,4,6,12 )Conc <- c (0,2,3,2,2.9,7.5,4,3,2,0,2.2,3.2,1.9,3,8,3,2.3,3.4,0.001,3,2,1.7,5,9,6,3.6,1.1 , 0.001,3.4,2.5,4.2,3.8,9.2,4.7,4.1,1.1,0,2.5,3.8,3.2,3.7,5,1.8,1.9,6.3,0,8,6,3.2,5.3,8.2,5.5,2.2,0.9 )DF <- data.frame(cbind(Subject,Day,Hour,Conc)) #---------------------------------------------------------------------------------------------------------------------------- # ----------- Compute Mean Concentration by Day and Hour.
#Edited code:
MeansByDayTime <- aggregate(as.double(DF$Conc),
by = list(Day = DF$Day, Hour=DF$Hour),
FUN =
function(x) c( mean = mean(x, trim = 0, na.rm = T,
weights=NULL),
sd = sd(x, na.rm=TRUE),
median = median(x, na.rm=TRUE),
min = min(x, na.rm=TRUE),
max = max(x, na.rm=TRUE)
)
)
# Show results
MeansByDayTime
I wish to tabulate into one data frame statistics summarizing concentration data. The summary is to include mean, standarddeviation, median, min and max. I wish to have summaries by Dose, Dayand Time. I can do this by calling aggregate once for each of the statistics (mean, standard deviation, median, min and max) and then execute 4 merges to merging the 5 data frames into one. (Example aggregate code for mean only is shown below.) Can someone show me the coding to do this as one command, rather than 5 calls to aggregate and 4 merges. In other words, in essence, I'd like to present to "FUN =" a list of functions, so all the summary stats come back in one data frame. Your assistance is appreciated. Thank you.Perhaps something like this?MeansByDoseDayTime <- aggregate(as.double(DF$Concentration), by = list(DF$Dose, DF$Day, DF$Time), FUN =function(x) c( mean(x, trim = 0, na.rm = T, weights=NULL), sd(x, na.rm=TRUE), median(x, na.rm=TRUE), min(na.rm=TRUE), max(x, na.rm=TRUE) ) )
David Winsemius, MD West Hartford, CT ______________________________________________ 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.
