[R] Get the difference of values to their own median value

From: Felix Wave <felix-wave_at_vr-web.de>
Date: Wed, 02 May 2007 09:44:16 +0200 (CEST)


Hello,
I've got a matrix (mail end) with the colnames x, y, z. In this matrix are different measurements. x and y are risign coordinates.

With the following line I got the median value of z for all "x" AND "y" witch are the same (not every measurment in my list hast the same number of "x" and "y" values. Sometimes lines are missing.
>MEDIAN <- na.omit( aggregate(INPUT[,3], by=list(INPUT[,2],INPUT[,1] ), FUN=median ) )

To see the failin of my measurments I want to get the difference between every measurment and the detected median values. The aim would be to have a list with different colums (for every measurment) with the difference between measurment 1,2,3, ..., x and the median.

Has anybody an idea?

I though I could split the measurment list. The beginning of every measurment can be found with
>START <- grep(" 0 0.0 0.00000000", INPUT)
But not every measurment has the same length and I don't have always the same number of measurments.

I hope you can help me.

Thank's a lot.
Felix

###############
## My R Code ##
###############
INPUT           <- readLines(dat.dat)
INPUT           <- gsub("^ ", "", INPUT)
INPUT           <- t( sapply( strsplit(INPUT, split=" "), as.numeric ) )
colnames(INPUT) <- c("x", "y", "z" )
#############
## dat.dat ##
#############
29 4.5 1.505713
29 4.6 1.580402

29 4.7 1.656875
29 4.8 1.735054
30 0 0
30 0.1 0.00096108
30 0.2 0.00323831
29 4.5 1.495148
29 4.6 1.568961
29 4.7 1.644467

30 0 0
30 0.1 0.00093699
30 0.2 0.00319411
30 0.3 0.00676619"

______________________________________________
R-help_at_stat.math.ethz.ch 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. Received on Wed 02 May 2007 - 07:48:36 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Wed 02 May 2007 - 13:31:53 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.