On 29-02-2012, at 09:45, Aniruddha Mukherjee wrote: > Hello R people, > > How can I compute the mean of the "Pulse_rate" column of the data frame or > matrix from the following character object called "str_got". It has 14 > entries and each entry has 8 values, separated by commas. Please go thru > the following R commands to know how I tried to unstring and unlist the > values to form a data frame. >> str_got > [1] "bp,67,2011-12-09T19:59:44.044+05:30,9830576102,68.0,124.0,58.0,66.0" > "bp,67,2011-12-09T20:19:31.031+05:30,9830576102,72.0,133.0,93.0,40.0" > ..... >> > matr<-matrix(unlist(strsplit(str_got, ",")), nrows, byrow=T)
nrows? I assume this was set somewhere in your script and not shown. Is it length(str_got)? >> matr > [,1] [,2] [,3] > [,4] [,5] [,6] [,7] [,8] > [1,] "bp" "67" "2011-12-09T19:59:44.044+05:30" "9830576102" "68.0" > ...... > Note column names must be inserted before computing the desired mean > value. > matr1<-as.data.frame(matr) Use matr1 <- as.data.frame(matr, stringsAsFactors=FALSE) If you don't dos tringsAsFactors=FALSE the column will be a factor and that is not equivalent with numeric. What's wrong with matr1$Pulse_rate <- as.numeric(matr1$Pulse_rate) Then you can calculate the desired mean with mean(matr1$Pulse_rate) or mean(matr1[,"Pulse_rate"]) Berend ______________________________________________ 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.