[R] Need Advice: Considering Converting a Package from S3 to S4
spencer.graves at prodsyse.com
Tue Aug 11 19:24:58 CEST 2009
Thanks for the comments. I too vastly prefer S3 to S4. Your
comparison is based on much greater experience than mine.
Could you please check the link you sent? I couldn't get it to
Terry Therneau wrote:
> For 90 percent of what I do I strongly prefer the loose (S3) rather than the
> rigid (S4) classes. So I'm closer to Rolf. My summary of S4 vs S3
> A large increment in
> 1. nuisance to write
> 2. difficulty to debug
> 3. ability to write very obscure code
> 4. design
> 5. ability to direct automatic conversions
> 6. validate the contents of a class object
> For simple objects 5 and 6 can be critical. Consider a date for instance,
> which will often be turned into a character, added or subtracted as a numeric,
> plotted, etc. Conversely, aspects of 1-4 are less worrisome for a simple
> object, particularly #4: I have a reasonable chance of "getting it right" the
> first time.
> For a complex object such as the result of a coxph fit
> fit <- coxph(Surv(time, status) ~ age + sex + treatment)
> #5 makes no sense at all: as.numeric(fit)??? Number 4 and 6 are really hard;
> after 15+ years of tuning I am still modifying the list of components in a coxph
> object. I know more about the computational aspects of Cox models than almost
> anyone and still it's not enough. Changes are harder with rigid classes.
> With reference to #3 above, for your amusement, look at
> the key line (to me) being "..every C++ programmer feels bound by some mystic
> promise to use every damm element of the languange on every project..."
> Terry T.
> R-help at r-project.org mailing list
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
Spencer Graves, PE, PhD
President and Chief Operating Officer
Structure Inspection and Monitoring, Inc.
751 Emerson Ct.
San José, CA 95126
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