[Rd] bug of *switch* function

[Jeff Ryan]

This isn't a bug in R.

You are assigning within the switch statement, and it is returning the
first TRUE value (human).

Use "=" not "<-"

species <- switch(organism, human="HS", fly="DM", yeast="SC")
> species
[1] "SC"


HTH
Jeff

On Mon, Mar 9, 2009 at 8:55 AM, guangchuang yu <guangchuangyu at gmail.com> wrote:
> Hi,
>
> When I call the *switch* function first time, it works. but when I call it
> at the second time, it does nothing. The version I use is R version 2.9.0
> Under development (unstable) (2009-02-21 r47969)
>
>
> here is the output:
>
>> organism="human"
>>     species <- switch(organism,
>        human <- "Hs",
>        fly <- "Dm",
>        mouse <- "Mm",
>        rat <- "Rn",
>        yeast <- "Sc"
>    )
>  species <- switch(organism,
> +   human <- "Hs",
> +   fly <- "Dm",
> +   mouse <- "Mm",
> +   rat <- "Rn",
> +   yeast <- "Sc"
> +  )
>> species
> [1] "Hs"
>> organism="yeast"
>>     species <- switch(organism,
>        human <- "Hs",
>        fly <- "Dm",
>        mouse <- "Mm",
>        rat <- "Rn",
>        yeast <- "Sc"
>    )
>  species <- switch(organism,
> +   human <- "Hs",
> +   fly <- "Dm",
> +   mouse <- "Mm",
> +   rat <- "Rn",
> +   yeast <- "Sc"
> +  )
>> species
> [1] "Hs"
>
>
> when I change *organism* to "yeast", and call *switch* function again,
> *species* suppose to be changed to "Sc", but it remain it's original value.
>
> You can see my screenshot at
> http://ygc.azpala.com/2009/03/09/bug-of-r-29-dev
>
> --
> Bests,
> Guangchuang Yu
>
> --~--~---------~--~----~------------~-------~--~----~
> Rm 848 Dept 9
> Institute of Radiation Medicine
> 27 Taiping Rd. Haidian Dist.
> Beijing, 100850, China
> Telephone: (86)-010-66931422
> Mobile: +86-13439009806
> Email: guangchuangyu at gmail.com
> -~----------~----~----~----~------~----~------~--~---
>
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>
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>



-- 
Jeffrey Ryan
jeffrey.ryan at insightalgo.com

ia: insight algorithmics
www.insightalgo.com