R help - Jul 2008 - looking for alternative of 'if-else'

There is "if-else" loop if I have to choose 1 item from a 2-item list.
However if I have a list of 4 items (let say) then how i can choose a single
item without employing 'if-else' loop? I mean in VBA I can use
"select-case", is there any equivalent in R as well?

Regards,

	[[alternative HTML version deleted]]

On 06/07/2008 4:59 AM, Arun Kumar Saha wrote:
> There is "if-else" loop if I have to choose 1 item from a 2-item
list.
> However if I have a list of 4 items (let say) then how i can choose a
single
> item without employing 'if-else' loop? I mean in VBA I can use
> "select-case", is there any equivalent in R as well?
See ?switch.

Duncan Murdoch

Why don't you try "switch" Let me assume that you want to
calculate
a=3 and b =5 by using one of "MEAN", "SUM","MIN",
and "MAX functions.
Then you could write your code: (If you want to calculate "MEAN")
> example<-function(fun=c("MEAN", "SUM",
"MIN", "MAX")){
+   fun<-match.arg(fun);a=3;b=5
+   switch(  fun,
+            MEAN=(a+b)/2,
+            SUM=a+b,
+            MIN=min(a,b),
+            MAX=max(a,b))
+            }
>             example("MEAN")
[1] 4
>
Hope this is helpful,
Chunhao Tu





Quoting Arun Kumar Saha <arun.kumar.saha at gmail.com>:
> There is "if-else" loop if I have to choose 1 item from a 2-item
list.
> However if I have a list of 4 items (let say) then how i can choose a
single
> item without employing 'if-else' loop? I mean in VBA I can use
> "select-case", is there any equivalent in R as well?
>
> Regards,
>
> 	[[alternative HTML version deleted]]
>
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