On 02-Aug-09 21:10:12, Noah Silverman wrote:
> Hi,
> I am reading in a dataframe from a CSV file. It has 70 columns.
> I do not have any kind of unique "row id".
>
> rawdata <- read.table("r_work/train_data.csv", header=T, sep=",",
> na.strings=0)
>
> When training an svm, I keep getting an error
> So, as an experiment, I wrote the data back out to a new file
> so that I could see what the svm function sees.
>
> write.table(rawdata, file="r_work/output_data.csv",
> quote=FALSE, sep=",")
>
> It appears as if R has added a column for me with id numbers
> for each row. That would be fine, except that R SHIFTS ALL MY
> COLUMN LABELS OVER ONE. That causes several problems:
> 1) The header names are now wrong for each column
> 2) My last column has no label
> 3) The SVM complains about the unlabeled column
>
> Would someone please help me sort this out.
> Thanks!
> -N
Not that the default for "row.names" in write.table() is TRUE.
So. in your caoomand, that is what you get. write.table() then
*creates* row-names (by default the row numbers). Compare:
D <- rbind(c(1.1,1.2,1.3),c(2.1,2.2,2.3),c(3.1,3.2,3.3))
D
# [,1] [,2] [,3]
# [1,] 1.1 1.2 1.3
# [2,] 2.1 2.2 2.3
# [3,] 3.1 3.2 3.3
write.table(D,file="withTRUE.csv",quote=FALSE,sep=",")
# withTRUE.csv:
# V1,V2,V3
# 1,1.1,1.2,1.3
# 2,2.1,2.2,2.3
# 3,3.1,3.2,3.3
write.table(D,file="withFALSE.csv",row.names=FALSE,quote=FALSE,sep=",")
# withFALSE.csv:
# V1,V2,V3
# 1.1,1.2,1.3
# 2.1,2.2,2.3
# 3.1,3.2,3.3
Hoping this helps,
Ted.
--------------------------------------------------------------------
E-Mail: (Ted Harding) <ted.hard...@manchester.ac.uk>
Fax-to-email: +44 (0)870 094 0861
Date: 02-Aug-09 Time: 22:35:04
------------------------------ XFMail ------------------------------
______________________________________________
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.
