determining if a function exists in a particular package

[Erin Hodgess-2]

Hello R People:

Is there a way to determine if a function exists in a particular
package, please?

I looked at exists and objects, but they seem to refer to an
environment rather than a package.

I was thinking of something like:

ifelse(exists(functiona) in MASS, print(1:10), print(5))

Thanks,
Erin


--
Erin Hodgess
Associate Professor
Department of Computer and Mathematical Sciences
University of Houston - Downtown
mailto: [hidden email]

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[Erin Hodgess-2]

I found the solution in an old post:

It's
lsf.str("package:ts")

for functions.

Cool!

On Fri, Apr 27, 2012 at 4:12 PM, Mark Leeds <[hidden email]> wrote:

> Hi Erin: I don't know how to do it programatically but it might be quicker
> to just
> go to the vignette and click on it. All the functions should be in the right
> column of
> the pdf. Of course, you may have reason for needing it programatically in
> which
> case, my apologies for the noise !!!!!
>
> On Fri, Apr 27, 2012 at 5:07 PM, Erin Hodgess <[hidden email]>
> wrote:
>>
>> Hello R People:
>>
>> Is there a way to determine if a function exists in a particular
>> package, please?
>>
>> I looked at exists and objects, but they seem to refer to an
>> environment rather than a package.
>>
>> I was thinking of something like:
>>
>> ifelse(exists(functiona) in MASS, print(1:10), print(5))
>>
>> Thanks,
>> Erin
>>
>>
>> --
>> Erin Hodgess
>> Associate Professor
>> Department of Computer and Mathematical Sciences
>> University of Houston - Downtown
>> mailto: [hidden email]
>>
>> ______________________________________________
>> [hidden email] mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
>

--
Erin Hodgess
Associate Professor
Department of Computer and Mathematical Sciences
University of Houston - Downtown
mailto: [hidden email]

______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

[Sarah Goslee]

You can also use exists():
> library(MASS)
> exists("loglm", where=search()[grepl("MASS", search())])
[1] TRUE
> exists("loglmx", where=search()[grepl("MASS", search())])
[1] FALSE

As for lsf.str(), this only works for loaded packages. You didn't
specify whether you needed to be able to search loaded packages,
installed packages, or packages that exist on CRAN.

Package sos might be helpful for the last of those; you can use
help.search and grep to search for functions within installed but
unloaded packages.

Since you didn't tell us anything about your objectives, it's
impossible to know what you are really looking for.

Sarah


On Fri, Apr 27, 2012 at 5:13 PM, Erin Hodgess <[hidden email]> wrote:

> I found the solution in an old post:
>
> It's
> lsf.str("package:ts")
>
> for functions.
>
> Cool!
>
> On Fri, Apr 27, 2012 at 4:12 PM, Mark Leeds <[hidden email]> wrote:
>> Hi Erin: I don't know how to do it programatically but it might be quicker
>> to just
>> go to the vignette and click on it. All the functions should be in the right
>> column of
>> the pdf. Of course, you may have reason for needing it programatically in
>> which
>> case, my apologies for the noise !!!!!
>>
>> On Fri, Apr 27, 2012 at 5:07 PM, Erin Hodgess <[hidden email]>
>> wrote:
>>>
>>> Hello R People:
>>>
>>> Is there a way to determine if a function exists in a particular
>>> package, please?
>>>
>>> I looked at exists and objects, but they seem to refer to an
>>> environment rather than a package.
>>>
>>> I was thinking of something like:
>>>
>>> ifelse(exists(functiona) in MASS, print(1:10), print(5))
>>>
>>> Thanks,
>>> Erin
>>>

--
Sarah Goslee
http://www.functionaldiversity.org

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and provide commented, minimal, self-contained, reproducible code.

[Gabor Grothendieck]

On Fri, Apr 27, 2012 at 5:13 PM, Erin Hodgess <[hidden email]> wrote:
> I found the solution in an old post:
>
> It's
> lsf.str("package:ts")
>
> for functions.
>
> Cool!
>

Note that that gives exported functions.  If you also want internal
functions in addition to the exported ones then try this:

library(ts)
lsf.str(asNamespace("ts"))

Also note that these not give functions whose name starts with dot
unnless all.names=TRUE is added as an argument.

--
Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com

______________________________________________
[hidden email] mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

[William Dunlap]

> I looked at exists and objects, but they seem to refer to an
> environment rather than a package.

Those functions work with the names of attached packages, but you have
know that the name of an attached package has "package:" prefixed to
the package's usual name.  E.g.,
  > exists("lm", "package:stats")
  [1] TRUE
  > objects("package:stats", pattern="iso")
  [1] "isoreg"
If you leave off the "package:" you might be misled into thinking an
environment is required:
  > objects("stats", pattern="iso")
  Error in as.environment(pos) : no item called "stats" on the search list

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com

> -----Original Message-----
> From: [hidden email] [mailto:[hidden email]] On Behalf
> Of Erin Hodgess
> Sent: Friday, April 27, 2012 2:08 PM
> To: R help
> Subject: [R] determining if a function exists in a particular package
>
> Hello R People:
>
> Is there a way to determine if a function exists in a particular
> package, please?
>
> I looked at exists and objects, but they seem to refer to an
> environment rather than a package.
>
> I was thinking of something like:
>
> ifelse(exists(functiona) in MASS, print(1:10), print(5))
>
> Thanks,
> Erin
>
>
> --
> Erin Hodgess
> Associate Professor
> Department of Computer and Mathematical Sciences
> University of Houston - Downtown
> mailto: [hidden email]
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.