[R] Making objects global in a package

[Jeff Newmiller]

Avoiding rda files because they don't track well with version control seems weak to me, since you should be creating the rda with an R file in the tools directory.

On July 13, 2018 6:50:31 PM PDT, William Dunlap <wdunlap using tibco.com> wrote:
>What the OP is doing looks fine to me.
>
>The environment holding the data vectors is not necessary, but it helps
>organize things - you know where to look for this sort of data vector.
>
>I would avoid the *.rda file, since it is not text, hence not readily
>editable
>or trackable with most source control systems.
>
>
>Bill Dunlap
>TIBCO Software
>wdunlap tibco.com
>
>On Fri, Jul 13, 2018 at 6:17 PM, Jeff Newmiller
><jdnewmil using dcn.davis.ca.us>
>wrote:
>
>> a) There is a mailing list for package development questions:
>> R-package-devel.
>>
>> b) This seems like a job for the sysdata.rda file... no explicit
>> environments needed. See the Writing R Extensions manual.
>>
>> On July 13, 2018 5:51:06 PM PDT, Michael Hannon <
>> jmhannon.ucdavis using gmail.com> wrote:
>> >Greetings.  I'm putting together a small package in which I use
>> >`dplyr::read_csv()` to read CSV files from several different
>sources.
>> >I do
>> >this in several different files, but with various kinds of
>subsequent
>> >processing, depending on the file.
>> >
>> >I find it useful to specify column types, as the apparent data type
>of
>> >a given
>> >column sometimes changes unexpectedly deep into the file.  I.e., a
>> >field that
>> >consistently looks like an integer, suddenly becomes a fraction:
>> >
>> >    1, 1, ..., 1, 1/2, 1, ...
>> >
>> >Hence, the column type has to be treated as a character, rather than
>as
>> >an
>> >integer (with the possibility of later conversion to double, if
>> >necessary).
>> >(This is just an example.)
>> >
>> >Therefore I use the `col_types` argument in all of the calls to
>> >`read_csv()`.
>> >
>> >These calls are spread over several files, but I want the keep all
>of
>> >the
>> >column types in a single place, yet have them available in each of
>the
>> >several
>> >files.  This is just for the sake of maintainability.
>> >
>> >At the moment I do this by putting the column-type definitions into
>a
>> >single,
>> >file:
>> >
>> >    000_define_data_attributes.R
>> >
>> >that:
>> >
>> >    (1) is named so that it's parsed first by `devtools::build()`
>> >    (2) sets up an environment and stuffs the column types into it:
>> >
>> >            data_env <- new.env(parent=emptyenv())
>> >            data_env$col_types_alpha <- list(
>> >                Date = col_date(),
>> >                var1 = col_double(),
>> >                ...
>> >            )
>> >
>> >There are a few other things that go into the file as well.
>> >
>> >Then I pick off the appropriate stuff from the environment in the
>other
>> >files:
>> >
>> >foo_alpha <- read_csv("alpha.csv", col_types =
>> >data_env$col_types_alpha)
>> >
>> >This seems to work, but it doesn't "feel" right to me.  (If this
>were
>> >Python,
>> >people would accuse me of being "non-pythonic").
>> >
>> >Hence, I'm seeking suggestions for the best practice for this kind
>of
>> >thing.
>> >
>> >BTW, I note that both the sources of data ("alpha", etc.) and the
>> >column types
>> >are more or less guaranteed to be static for the foreseeable future.
>> >Hence,
>> >there really isn't much danger in just replicating the column-type
>> >definitions
>> >in each of the various files, which would obviate the need for the
>> >"000..."
>> >file.  In other words, this is mostly a style thing.
>> >
>> >Thanks for any advice you can provide.
>> >
>> >-- Mike
>> >
>> >______________________________________________
>> >R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> >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.
>>
>> --
>> Sent from my phone. Please excuse my brevity.
>>
>> ______________________________________________
>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> 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.
>>

-- 
Sent from my phone. Please excuse my brevity.