Re: [R] value changed after paste() function

From: Bert Gunter <gunter.berton_at_gene.com>
Date: Mon, 21 Mar 2011 09:32:35 -0700

Inline below.

On Mon, Mar 21, 2011 at 8:18 AM, kellysong <song.qiao_at_student.dit.ie> wrote:
> Hi all,
>
> I am new user in R, I am trying to to use paste function to concatenate
> strings which has been fetched from database table(postgres database), the
> following are my code:
>
> when i do:
>  > sqlFetch(channel,'transactions')
>
> outputs are following(only parts, there are around 200 transactions in
> total)
>
>    orderid productname price quantity discount
> 1    T10248      potato  1.80       10     0.00
> 2    T10248      sweets  2.00        5     0.00
> 3    T10249        milk  1.99        9     0.00
> 4    T10249       apple  2.35       40     0.00
>
>
> when i do:
>> paste(sqlFetch(channel,'transactions'))
>
> outputs are:
> [1] "c(1, 1, 2, 2)"
> [2] "c(7, 8, 6, 1)"
> [3] "c(1.8, 2, 1.99, 2.35) "
> [4] "c(10, 5, 9, 40)"
> [5] "c(0, 0, 0, 0) "
>
>
> any idea why the orderid and the productname have been changed?? and what

The results of sqlFetch is a data frame whose alphanumeric columns are factors. You need to spend some (more) time with "An Introduction to R" learning about R's data structures and basic procedures BEFORE you start using it. After you have done so,

?do.call

and

?factor

will tell you how to deal with this sort of thing. But it is doubtful that you will understand until you have first spent some time with the basic docs.

> should i do to solve this??
>
> Any help would be very appreciated!
>
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/value-changed-after-paste-function-tp3393845p3393845.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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.
>

-- 
Bert Gunter
Genentech Nonclinical Biostatistics
467-7374
http://devo.gene.com/groups/devo/depts/ncb/home.shtml

______________________________________________
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 Mon 21 Mar 2011 - 16:36:11 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 Mon 21 Mar 2011 - 16:40:23 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.

list of date sections of archive