> I built a 1,273,230 by 6 data set named "mydata2", it was saved
in the
> following command,
>
> write.table(mydata2, "mydata2.txt",
row.name=F,col.name=T,quote=F,sep="\t")
>
> The next day I read in above saved text file into R,
>
>
temp<-read.table("mydata2.txt",header=T,sep="\t",na.strings="NA")
>
> However, the dimension of "temp" is 636,615 X 6.
A wild guess: does your table contain strings which include single or
double ticks? As you are not disabling quoting in read.table this can
cause problems:
> foo = data.frame(a=c("abc","5'foo","xxx",
"3'bar"), b=1:4)
> foo
a b
1 abc 1
2 5'foo 2
3 xxx 3
4 3'bar 4
> write.table(foo, "mydata2.txt",
row.name=F,col.name=T,quote=F,sep="\t")
> foo <-
read.table("mydata2.txt",header=T,sep="\t",na.strings="NA")
> foo
a b
1 abc 1
2 5foo\t2\nxxx\t3\n3bar 4
> foo <-
read.table("mydata2.txt",header=T,sep="\t",na.strings="NA",
quote='')
> foo
a b
1 abc 1
2 5'foo 2
3 xxx 3
4 3'bar 4
The same aplies to comment characters embedded in strings.
If this is not your problem, I'd first check if the file has the
expected number of lines.
cu
Philipp
--
Dr. Philipp Pagel
Lehrstuhl f?r Genomorientierte Bioinformatik
Technische Universit?t M?nchen
Wissenschaftszentrum Weihenstephan
85350 Freising, Germany
http://mips.gsf.de/staff/pagel