On Feb 16, 2010, at 4:40 PM, David Winsemius wrote:
On Feb 16, 2010, at 2:25 PM, Hichem Ben Khedhiri wrote:
Dear R-helpers,
I am using a vrtest on time series data. My commands are as follows;
read.table("B.txt",sep="\t",fill=TRUE, na.strings = "NA")
require(vrtest)
rm(list=ls(all=TRUE))
datamat <- read.table("B.txt",sep="\t",fill=TRUE, na.strings = "NA")
column <- 1
nob <- nrow(datamat)
y <- log(datamat[2:nob,column])-log(datamat[1:(nob-1),column])
After, the use of last command, I get the following message;
in Math.factor(c(37L, 36L, 42L, 41L, 44L, 38L, 31L, 61L, 66L, 91L, :
log not meaningful for factors
My data is composed of one column.
It appears that you may need to apply as.numeric(as.character( )) to
that column after input (See the FAQ if you don't know why you need
both functions.) You seem to have created a factor in datamat. You
can prevent factor-formation with stringsAsFactors or colClasses
arguments to read.table.
OOOPs. I did not notice that you had attached the file. It's not a tab
separated file and so both of your columns get read in as one
character variable. (or maybe they are commas as decimal points in
which case see below.) You also did not tell read.table() that you
had a header and furthermore to completely complicate things, you
enclosed the two columns within paired double-quotes.
Get rid of the enclosing quotes and read back in with correct
arguments, perhaps sep="," unless you are in a locale that uses commas
as decimal points, in which case you only need read.csv2(). The
fill=TRUE appears superfluous.
I would appreciate, if any one could provide me with some hints to
get
around the problem.
Best regards,
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
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David Winsemius, MD
Heritage Laboratories
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.
