On Mon, Mar 9, 2009 at 8:55 AM, guangchuang yu
asked why switch(..., a <- 3, ...) doesn't
have the same effect as switch(..., a=3, ...).
In most contexts, `<-` and `=` are synonymous in R, and mean
assignment. In function-argument position, however, an infix `=` names
the argument. Switch depend
Because "<-" assigs a value. It does not name the alternatives.
Again, please read ?switch.
These two examples are the same:
> organism <- 'foo'
> (species <- switch(organism, human <- "HS", fly <- "DM", yeast <- "SC"))
[1] "HS"
> (species <- switch(organism, "HS", "DM", "SC"))
[1] "HS"
Josh
--
But Why ?
Why can not use "<-" ?
On Mon, Mar 9, 2009 at 10:31 PM, Jeff Ryan wrote:
> 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
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 wrote:
> Hi,
>
> W
guangchuang yu 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"
>> specie
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
