Re: [R] paste / system mystery

From: Uwe Ligges <ligges_at_statistik.uni-dortmund.de>
Date: Tue 16 Aug 2005 - 03:52:11 EST

ivo_welch-rstat8303@mailblocks.com wrote:

> Dear R wizards:
>
> under R-2.1.0:
>
> eargs <- 3:5;
> line <- paste(c("echo A B", eargs));
> cat("executing from R: '", line, "'\n");
> system(line);
>
> Oddly, only "A" and "B" are echoed, not the eargs. I had hoped that
> line would be one string at this point, and for printing this seems to
> be true. However, unlist(line) still gives me the 4 components. It
> almost seems like the objects were not really pasted, but kept separate
> [perhaps to conserve memory]---which works internally, but not
> externally.
>
> Is this my poor understanding of R, an R "feature," or an R bug?

Feature:
The arguments of paste() get pasted, and you have just specified one argument which is a character *vector*.
You want to say that the elements of the vector should be pasted as follows:

line <- paste(c("echo A B", eargs), collapse = " ")

Uwe Ligges

> help appreciated.
>
> /iaw
>
>
> ---
> ivo welch
>
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R-help@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 Received on Tue Aug 16 04:05:20 2005

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