[R] Variable passed to function not used in function in select=... in subset

Wacek Kusnierczyk Waclaw.Marcin.Kusnierczyk at idi.ntnu.no
Tue Nov 11 11:27:30 CET 2008

Berwin A Turlach wrote:
> On Tue, 11 Nov 2008 09:27:41 +0100
> Wacek Kusnierczyk <Waclaw.Marcin.Kusnierczyk at idi.ntnu.no> wrote:
>> but then it might be worth asking whether carrying on with misdesign
>> for backward compatibility outbalances guaranteed crashes in future
>> users' programs, [...]
> Why is it worth asking this if nobody else asks it?  Most notably a
> certain software company in Redmond, Washington, which is famous for
> carrying on with bad designs and bugs all in the name of backward
> compatibility.  Apparently this company also sets industry standards so
> it must be o.k. to do that. ;-)

sure.  i have had this analogy in mind for a long time, but just didn't
want to say it aloud.  indeed, r carries on with bad design, but since
there are more and more users, it's just fine.

>> which result in confused complaints, 
> Didn't see any confused complaints yet.  

really.  the discussion was motivated precisely by a user's complaint. 
just scan this list;  a large part of the questions stems from
confusion, which results directly from r's design. 

> Only polite requests for
> enlightenment after coming across behaviour that useRs found surprising
> given their knowledge of R.  The confused complaints seem to be posted
> as responses to responses to such question by people who for what ever
> reason seem to have an axe to grind with R. 
>> the need for responses suggesting hacks to bypass the design, 
> Not to bypass the design, but to achieve what the person whats.  As any
> programming language, R is a Turing machine and anything can be done
> with it; it is just a question how.

yes, to bypass the design.  to achieve what one would normally expect an
expression to be evaluated to, but r does it differently.

>> and possibly incorrect results published 
> I guess such things cannot be avoided no matter what software you are
> using.  I am more worried about all the analysis done in MS Excel, in
> particular in the financial maths/stats world.  Also, to me it seems
> that getting incorrect results is a relative small problem compared with
> the frequent misinterpretation of correct results or the use of
> inappropriate statistical techniques.  

could not agree more, which does oppose in any way my complaints.

>> because r is likely to do everything but what the user expects.
> This is quite a strong statement, and I wonder what the basis is for
> that a statement.  Care to provide any evidence?

i could think of organizing a (don't)useR conference, where submissions
would provide such evidence.  whatever i say here, is mostly discarded
as nonsense comments (while it certainly isn't), you say i make the
problem up (while i just follow up user's complaints).  seriously, i may
have exaggerated in the immediately above, but lots of comments made
here by the users convince me that r very often breaks expectations.

> R is a tool; a very powerful one and hence also very sharp.  It is easy
> to cut yourself with it, but when one knows how to use it gives the
> results that one expects.  I guess the problem in this age of instant
> gratification is that people are not willing to put in the time and
> effort to learn about the tools they are using.  

but a good tool should be made with care for how users will use it.  r
apparently fits the ideas of its developers, while confuses naive
users.  i do not opt for redmond-like 'i know better what you want'
intelligence, but i think some of the confusions should be predicted and
the design tuned accordingly.

> How about spending some time learning about R instead of continuously
> griping about it?  Just imagine how much you could have learned in the
> time you spend writing all those e-mails. :)

i learn a lot while writing these emails, because i do read manuals and
make up tests.  but there would be little progress if we all were buying
what we are given instead of critically examining it.  i can stop
posting at any moment, but i don't think it would help the community ;)

>> r suffers from early made poor decisions, but then this in itself is
>> not a good reason to carry on.
> Radford Neal is also complaining on his blog
> (http://radfordneal.wordpress.com/) about what he thinks are design
> flaws in R.  Why don't you two get together and design a good
> substitute without any flaws?  Or is that too hard? ;-)

it's certainly hard to design and implement a system of the size of r. 
it's certainly easier to just complain rather than make a better tool. 
but it would really be a pitiful world if all of us were just
developing, and no one would criticize.  my purpose is not (or not just,
if you prefer) to annoy the r team, but to point out and document issues
that really need rethinking.  discouragingly, many of these issues
appear to be known already, but simply ignored. 


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