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

Berwin A Turlach berwin at maths.uwa.edu.au
Tue Nov 11 18:21:31 CET 2008

On Tue, 11 Nov 2008 12:53:31 +0100
Wacek Kusnierczyk <Waclaw.Marcin.Kusnierczyk at idi.ntnu.no> wrote:

> but seriously, when one buys a complicated device one typically reads
> a quick start guide, and makes intuitive assumptions about how the
> device will work, turning back to the reference when the expectations
> fail. good design should aim at reducing the need for checking why an
> intuitive assumption fails.

And on what are these intuitive assumptions based if not on familiarity
with similar devices?  And people have different intuition, why should
yours be the correct one and the golden standard?

I know that if I buy a complicated device and never owned something
similar I read more than the quick start guide to get familiar with the
device before breaking something due to using wrong assumptions.

When I started to use S-PLUS, I had used GAUSS before.  Still I took
the time off to work through the blue book and make myself familiar
with S-PLUS before using it for serious work.  Based on my experience
with R, I found R very intuitive and easy to use; but still try to keep
up with relevant documentation.

It really seems that your problem is that you have an attitude of
wanting to have instant gratification.

> > If you do not care about how to use machine-gun correctly you could
> > easily harm yourself or others. 
> >   
> indeed, and i'm scared to think that some of the published research
> can be harmful because the researcher denied to read the whole r
> reference before doing a stats analysis.

Sorry, but this is absolute rubbish.  There are plenty of statistical
analyses that can be done without reading the complete R reference.
However, one or two good books might help.

My concern would rather be that everybody thinks that they can do
statistics and that software project of R makes such people really
think they can do it.  I am far more concerned about inappropriate
analyses and wrong interpretations.  How often is absence of evidence
taken as evidence of absence?

> you see, i'm not complaining about my own analyses failing because i
> have not read the appropriate section in the reference.  if this were
> the problem, i'd just read more and keep silent.
> i'm complaining about the need to read, by anyone who starts up with
> r, in all gory details, about the intricacies of r before doing
> anything, because the behaviour is often so unexpected.  

I guess Frank Harrell had people like you in mind when he wrote:

Would you also not expect to learn about surgery in all its gory
details before attempting brain surgery because brain surgery is so
intuitive and doesn't need any study?

Believe it or not, there are lots of useful things that you can do in R
without knowing all the gory details.  There are even people who got
books on R published who obviously don't know all the gory details and
they still show useful applications of R.



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Berwin A Turlach                            Tel.: +65 6515 4416 (secr)
Dept of Statistics and Applied Probability        +65 6515 6650 (self)
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