[R] A slight trap in read.table/read.csv.

[Petr PIKAL]

Hi

r-help-bounces at r-project.org napsal dne 09.03.2010 01:44:38:

> 
> On 9/03/2010, at 11:17 AM, Mike Prager wrote:
> 
> > Rolf Turner <r.turner at auckland.ac.nz> wrote:
> >> 
> >> I solved the problem by putting in a colClasses argument in my
> >> call to read.csv().  But I really think that the read functions
> >> are being too clever by half here.  If field entries are surrounded
> >> by quotes, shouldn't they be left as character?  Even if they are
> >> all F's and T's?
> >> 
> >> Furthermore using F's and T's to represent TRUE's and FALSE's is
> >> bad practice anyway.  Since FALSE and TRUE are reserved words it
> >> would make sense for the read function to assume that a field is
> >> logical if it consists entirely of these words.  But T's and F's
> >> .... I don't think so.
> >> 
> >> I would argue that this behaviour should be changed.  I can see no
> >> downside to such a change.
> >> 
> > 
> > I agree with you, Rolf, that this is horrid behavior. It is such
> > automatic devices that have made people hate (e.g.) Microsoft
> > Word with a passion. 
> > 
> > Yet, in R this is a designed-in bug (e.g., feature) that
> > probably can't be changed without making some legacy code not
> > work. But at least, T and F could be removed soon as synonms for
> > TRUE and FALSE. We have seen that "_" was removed as an
> > assignment operator, and the world did not crumble. The use of T
> > and F is no less error-prone, and possibly more.
> 
>    I would definitely support the removal of the use of T
>    and F for TRUE and FALSE.  Some code would break, but
>    it would be easy to trace the source of the problem and
>    easy to fix.

I would respectfully oppose it. It may be quite convenient for making code 
for functions and other programming stuff but all using R more or less in 
interactive way this change could be quite a burden especially when there 
are many functions which use TRUE/FALSE for setting its parameters.

In those (and many others) instances I almost exclusively use T/F 
shortcut.

read.delim(file, header = TRUE, sep = "\t", quote="\"", dec=".", fill = 
TRUE, comment.char="", ...)
lm(formula, data, subset, weights, na.action,method = "qr", model = TRUE, 
x = FALSE, y = FALSE, qr = TRUE,     singular.ok = TRUE, contrasts = NULL, 
offset, ...)

If this had to be changed I would vote for some change which allow users 
some other shortcut for setting interactively parameters in functions.

Regards
Petr
 


> > 
> > The only immediate solution to this accretion of overly clever
> > behavior would be for someone to write new functions (say,
> > Read.csv) that didn't do all those conversions behind the
> > scenes. I'm not about to do that. Are you?
> 
> 
>    NFL!!!
> 
>       cheers,
> 
>          Rolf
> 
> ######################################################################
> Attention:\ This e-mail message is privileged and confid...{{dropped:9}}
> 
> ______________________________________________
> 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.