R help - May 2007 - Get the difference of values to their own median value

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"

Use ave.  Also its easier to use read.table to read it in and then
convert it to a matrix if that's what you want.

Input <- "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"

cn <- c("x", "y", "z")
# replace next line with this:
#  INPUT <- as.matrix(read.table("dat.dat", col.names = cn))
INPUT <- as.matrix(read.table(textConnection(Input), col.names = cn))

INPUT[,3] - ave(INPUT[,3], INPUT[,1], INPUT[,2], FUN = median)



On 5/2/07, Felix Wave <felix-wave at vr-web.de>
wrote:
> 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"
>
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