[R] SAS Macro Variable in R

[Don MacQueen]

I typically do something like this:

  nm <- 'TEF'

## split into multiple lines only to make it easier to read
dpath <- paste('http:// ichart.yahoo.com/table.csv?s=',
                        nm,
 
'.MC&a=00&b=1&c=2003&d=05&e=23&f=2009&g=d&ignore=.csv',   sep='')

download.file( dpath, 'c:\\projects\\stock data\\data\\test.csv',quiet=TRUE)

Then just change the value of nm to different letters.

I have also used the sub() or gsub() approach like Thomas, and the 
"wrap it in a function" approach like David, though I would use 
paste() inside the function, not the substitute() that he uses.

So you see, R tends to have multiple ways to do things.

-Don

At 7:40 PM +0200 6/23/09, David Young wrote:
>Hi I'm new to R and would like to implement a SAS-like macro variable
>in R.
>
>What I'd like to do is take the simple R code below and change the
>"=TEF" to different letters to refer to different companies' data for
>download.
>
># DOWNLOADS FILES FROM YAHOO INTERNET
>download.file('http:// 
>ichart.yahoo.com/table.csv?s=TEF.MC&a=00&b=1&c=2003&d=05&e=23&f=2009&g=d&ignore=.csv',
>  'c:\\projects\\stock data\\data\\test.csv',quiet=TRUE)
>
>As you can see the text I want to change is within the quoted Internet
>address.  Is this possible in R?
>
>Thanks in advance for any assistance.
>
>
>
>--
>Best regards,
>
>David Young
>Marketing and Statistical Consultant
>Madrid, Spain
>+34 913 540 381
>http:// www. linkedin.com/in/europedavidyoung
>
>                           mailto:dyoung at telefonica.net
>
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>and provide commented, minimal, self-contained, reproducible code.


-- 
--------------------------------------
Don MacQueen
Environmental Protection Department
Lawrence Livermore National Laboratory
Livermore, CA, USA
925-423-1062