Re: [R] Why is conversion not working?

From: jim holtman <jholtman_at_gmail.com>
Date: Mon, 17 Dec 2007 20:11:37 -0500

try this:

> x <- data.frame(month=as.character(sample(1:12,1000,TRUE)),
+ year=as.character(sample(c(0:7, 95:99), 1000, TRUE)), stringsAsFactors=FALSE)
> # convert to integer
> x$Year <- as.integer(x$year)
> # now add the century
> x$Year <- ifelse(x$Year < 10, x$Year+2000, x$Year+1900)
>
>
> head(x)

  month year Year
1 10 96 1996

2     9    5 2005
3     8   95 1995
4     1    7 2007
5    11    3 2003
6     2   99 1999

>

On Dec 17, 2007 7:52 PM, Jonas Malmros <jonas.malmros_at_gmail.com> wrote:
> I have a data frame, where two last columns - "month" and "year" - are
> character vectors. The "year" vector is made of two numbers (i.e. "97"
> for 1997, "07" for 2007, etc)
> What I want to do is to create a variable "Year" that is mode numeric
> and where each record is a four-figure number (1997, 2007,...)
> I have about 40000 rows in the dataframe, the observations are for 10
> years (so there are multiple rows for each year).
> I tried the following, but the program runs and runs, and if I abort
> it all the years in "Year" are 1997:
>
> for(i in 1:dim(database)[1]){
> if(database$year[i]>90) {
> database$Year[i] <- as.numeric(database$year[i])+1900 } else {
> database$Year[i] <- as.numeric(database$year[i])+2000
> }
> }
>
> Thanks in advance for explanations.
>
> Regards,
> JM
>
> --
> Jonas Malmros
> Stockholm University
> Stockholm, Sweden
>
> ______________________________________________
> R-help_at_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.
>

-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?

______________________________________________
R-help_at_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.
Received on Tue 18 Dec 2007 - 01:14:08 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Tue 18 Dec 2007 - 01:30:19 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.