Homework 2: Run a preprocessing analysis for an example dataset.

To do this homework follow these instructions:

1. Set the location of the dataset in the URL address dialog.
The dataset for this example is:
http://www.rci.rutgers.edu/~cabrera/DNAMR/hw2.txt

2. Copy the code at the bottom of the paste and paste it into the text box below.

3. Click on the submit button

4. The first line of the code contains the the value for the constant k = 0. You may replace it by a value of your choice in orfer to modify the transformation to log(X-k). Be careful that number the number k has to be less than the minimum of x, otherwise you will take the log of a negative number. One option is k= min(X)* 0.95

External Data Entry

Enter a dataset URL :

Or

Select a local file to submit: 

##
##
k=0 ##
#
pre.summary <- function(x,k=0,npages=1 ) { # Summary about transformations
        p <- ncol(x)
        x <- data.frame(x)
        pp = ceiling(p/npages)
        par(mfcol=c(4,pp))
        par(mar=c(3,1,3,1))
        nam <- names(x)
        nam1 <- paste ("Log(",nam,")",sep="")
        lx <- log(x-k)
        for( i in 1:p) {
          hist(x[[i]],main=nam[i])
          qqnorm(x[[i]],main=nam[i])
          hist(lx[[i]],main=nam1[i])
          qqnorm(lx[[i]],main=nam1[i])
        }
        invisible()  ##
} ###
#
#
min(X)
pre.summary(X,k)
#
#