R help - Jan 2007 - Treatment for Unequal Column Lengths?

Fellow R Users:

I have a .csv dataset that I have brought into R via read.table (and also
via read.csv). The dataset has columns that are not equal in length.
Essentially, this data file has vectors/columns in which I plan to use
different analyses on, hence they are unequal in length. Also, the columns
are either numeric or calendar dates. Is there a way to prevent R from
appending "NA"s to the numeric columns that are not the longest? Is
there a
way to prevent R from appending blank cells to the columns of dates in the
dataset that are not the longest? In other words, I'd like to have R
maintain each column's length.

I am aware that I can use "na.omit" before calling each numeric column
in my
analysis in order to work with the subset of that column that does not
contain the "NA" values. However, the na.omit command does not work
when R
appends blank cells to my date column lengths. Is there something analogous
to "na.omit" that I might be able to use when I am working with a
column of
dates to ignore the blank cells?

Further, I am curious as to whether there is an option that one might use
when the dataset is read in to R in order to keep all the column lengths as
they are. Any ideas/hints would be very much appreciated.

platform i386-pc-mingw32

arch i386

os mingw32

system i386, mingw32

status

major 2

minor 3.1

year 2006

month 06

day 01

svn rev 38247

language R

Thank you,

Dave H

	[[alternative HTML version deleted]]

One of the ways that R (and S-plus) is different from most other stats
packages (all that I can think of) is that it forces you to think about
your data up front.  This is a good thing.  It sounds like you really
have multiple datasets in one file, it is best to read them into R as
separate datasets, not try to force them into 1 dataset (like other
packages do).  If you need to keep the multiple datasets grouped
together you can combine them together in a list.

To read one dataset out of the file you can use read.table (read.csv)
with the colClasses (set other columns to "NULL") and nrows to grab
just
the columns and rows from a given dataset.  I would recommend writing a
script to read each of the separate pieces.

Hope this helps,

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at intermountainmail.org
(801) 408-8111
 
 
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Gerald Gamoric
> Sent: Thursday, January 11, 2007 9:52 AM
> To: r-help at stat.math.ethz.ch
> Subject: [R] Treatment for Unequal Column Lengths?
> 
> Fellow R Users:
> 
> I have a .csv dataset that I have brought into R via 
> read.table (and also via read.csv). The dataset has columns 
> that are not equal in length.
> Essentially, this data file has vectors/columns in which I 
> plan to use different analyses on, hence they are unequal in 
> length. Also, the columns are either numeric or calendar 
> dates. Is there a way to prevent R from appending "NA"s to 
> the numeric columns that are not the longest? Is there a way 
> to prevent R from appending blank cells to the columns of 
> dates in the dataset that are not the longest? In other 
> words, I'd like to have R maintain each column's length.
> 
> I am aware that I can use "na.omit" before calling each 
> numeric column in my analysis in order to work with the 
> subset of that column that does not contain the "NA" values. 
> However, the na.omit command does not work when R appends 
> blank cells to my date column lengths. Is there something 
> analogous to "na.omit" that I might be able to use when I am 
> working with a column of dates to ignore the blank cells?
> 
> Further, I am curious as to whether there is an option that 
> one might use when the dataset is read in to R in order to 
> keep all the column lengths as they are. Any ideas/hints 
> would be very much appreciated.
> 
> platform i386-pc-mingw32
> 
> arch i386
> 
> os mingw32
> 
> system i386, mingw32
> 
> status
> 
> major 2
> 
> minor 3.1
> 
> year 2006
> 
> month 06
> 
> day 01
> 
> svn rev 38247
> 
> language R
> 
> Thank you,
> 
> Dave H
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at stat.math.ethz.ch 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.
>