R help - Aug 2012 - Problem with global variable building a package

Hi,

 

My name is
Eva and this is my first message here. My English is not very good, but I hope
you can understand my question, in the context of an academic project.

 

I have
developed several functions in R and the
idea is that the user can access functions in order to:

 

1)     
Alter
parameters in relation with data and type of analysis.

2)     
Run
statistical analysis (Text and pdf files with results will be generated).

3)     
View
the value of the most important parameters.

 

All the
parameters I need are stored in a list object, and this list is used in all the
functions along the cycle performed by the user, but I would like the user does
not need to pass the name of the list as argument when he/she runs the different
functions, so I think I need to treat the list as a global variable.

 

Firstly, I
used the global assignment operator (“<<-“); secondly, I used “get” and
“assign”
functions and even I used a new.env() in order to use a new environment
exclusively for my list. However, when I try to build a package with all my
functions I don’t reach this end, because of an error in parse process.

 

My question
for you is the following: taking into account that my end is to build a
package, what can I do with this “global” list?. How can I treat it?.

 

Thanks in
advance.

 

Regards,

Eva

 


	[[alternative HTML version deleted]]

On Tue, Aug 7, 2012 at 2:09 AM, Eva Prieto Castro <evapcastro at yahoo.es>
wrote:
>
>
> Hi,
>
>
>
> My name is
> Eva and this is my first message here. My English is not very good, but I
hope
> you can understand my question, in the context of an academic project.
>
>
>
> I have
> developed several functions in R and the
> idea is that the user can access functions in order to:
>
>
>
> 1)
> Alter
> parameters in relation with data and type of analysis.
>
> 2)
> Run
> statistical analysis (Text and pdf files with results will be generated).
>
> 3)
> View
> the value of the most important parameters.
>
>
>
> All the
> parameters I need are stored in a list object, and this list is used in all
the
> functions along the cycle performed by the user, but I would like the user
does
> not need to pass the name of the list as argument when he/she runs the
different
> functions, so I think I need to treat the list as a global variable.
>
>
>
> Firstly, I
> used the global assignment operator (?<<-?); secondly, I used ?get?
and ?assign?
> functions and even I used a new.env() in order to use a new environment
> exclusively for my list. However, when I try to build a package with all my
> functions I don?t reach this end, because of an error in parse process.
>
>
>
> My question
> for you is the following: taking into account that my end is to build a
> package, what can I do with this ?global? list?. How can I treat it?.
Hi Eva,

I was actually doing something similar just the other day -- for a
"quick and dirty" solution, you can use assignInNamespace() or
assignInMyNamespace() but the help pages suggest CRAN won't look
kindly thereupon. To avoid that, I simply used a hidden [starting with
a dot] variable in the user's global environment (i.e., I defined it
on package load with the .onAttach() function and then just referenced
it when needed) but the best practices solution is probably to use
options() or something similar. See, e.g., setCompilerOptions() of the
compiler package or setRmetricsOptions() of the Rmetrics bundle.

Best,
Michael

>
>
>
> Thanks in
> advance.
>
>
>
> Regards,
>
> Eva
>
>
>
>
>         [[alternative HTML version deleted]]
>
>
> ______________________________________________
> R-help at r-project.org 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.
>

Probably the best thing to do is create an environment within the
package that you can assign to and read from.

Somewhere in the source code for the package include a line like:

my.env <- new.env()

then within any functions defined after that line you can set
variables within the environment with code like:

  my.env$paramA <- 3

and other functions can then read my.env$paramA.  This way you don't
need to worry about assign or <<- and all your functions will have
access to the same set of variables (but they won't interfere with the
users workspace).

On Tue, Aug 7, 2012 at 1:09 AM, Eva Prieto Castro <evapcastro at yahoo.es>
wrote:
>
>
> Hi,
>
>
>
> My name is
> Eva and this is my first message here. My English is not very good, but I
hope
> you can understand my question, in the context of an academic project.
>
>
>
> I have
> developed several functions in R and the
> idea is that the user can access functions in order to:
>
>
>
> 1)
> Alter
> parameters in relation with data and type of analysis.
>
> 2)
> Run
> statistical analysis (Text and pdf files with results will be generated).
>
> 3)
> View
> the value of the most important parameters.
>
>
>
> All the
> parameters I need are stored in a list object, and this list is used in all
the
> functions along the cycle performed by the user, but I would like the user
does
> not need to pass the name of the list as argument when he/she runs the
different
> functions, so I think I need to treat the list as a global variable.
>
>
>
> Firstly, I
> used the global assignment operator (?<<-?); secondly, I used ?get?
and ?assign?
> functions and even I used a new.env() in order to use a new environment
> exclusively for my list. However, when I try to build a package with all my
> functions I don?t reach this end, because of an error in parse process.
>
>
>
> My question
> for you is the following: taking into account that my end is to build a
> package, what can I do with this ?global? list?. How can I treat it?.
>
>
>
> Thanks in
> advance.
>
>
>
> Regards,
>
> Eva
>
>
>
>
>         [[alternative HTML version deleted]]
>
>
> ______________________________________________
> R-help at r-project.org 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.
>


-- 
Gregory (Greg) L. Snow Ph.D.
538280 at gmail.com