[Rd] (PR#8337) formatC adds leading space -- on some Windoze

[ripley@stats.ox.ac.uk]

On Tue, 22 Nov 2005 maechler at stat.math.ethz.ch wrote:

>>>>>> "KevinW" == Kevin Wright <kwright68 at gmail.com>
>>>>>>     on Mon, 21 Nov 2005 18:13:36 +0100 (CET) writes:
>
>    KevinW> Full_Name: Kevin Wright
>    KevinW> Version: 2.2.0
>    KevinW> OS: Windows 2000
> 	        ^^^^^^^
> this must be part of the problem

It is, and it is a known inconsistency with Linux (but I do not consider 
it to be a bug or `wrong behavior' or not `reasonable').

Windows always uses three digits for the exponent, e.g. E+001. This 
results from adjusting the returned result to be more consistent with 
other platforms.  (BTW, since width (sic) is a lower bound, it _is_ 
respected.)  Even if the layout is not ideal, the results are at least 
diff-able against those from other platforms.

If Kevin (or anyone else) wants it done even more consistently, he could 
contribute a patch.  Now, we _have_ done that for print(), but it did not 
seem worth it for formatC (especially as sprintf() is now widely used and 
would also need to be made consistent). (It also did not seem worth it 
given how little credit is given for such work.)


>    KevinW> Submission from: (NULL) (170.54.58.4)
>
>
>
>    KevinW> Apologies if my expectations (or reading of the man page) are incorrect.
>
>    KevinW> I seem unable to left-justify exponential format
>    KevinW> numbers.  There appears to always be an extra space
>    KevinW> inserted to the left.
>
>    KevinW> Using the example from the formatC help page:
>
>    R> xx  <- pi * 10^(-5:4)
>
>    R> cbind(formatC(xx, wid = 9, flag = "-"))
>    KevinW>      [,1]
>    KevinW> [1,] " 3.142e-05"
>    KevinW> [2,] "0.0003142"
>    KevinW> [3,] "0.003142 "
>    KevinW> [4,] "0.03142  "
>    KevinW> [5,] "0.3142   "
>    KevinW> [6,] "3.142    "
>    KevinW> [7,] "31.42    "
>    KevinW> [8,] "314.2    "
>    KevinW> [9,] "3142     "
>    KevinW> [10,] " 3.142e+04"
>
> which is also not obeying the 'wid' argument.
>
> I get something much more reasonable:
>
>      [,1]
> [1,] "3.142e-05"
> [2,] "0.0003142"
> [3,] "0.003142 "
> [4,] "0.03142  "
> [5,] "0.3142   "
> [6,] "3.142    "
> [7,] "31.42    "
> [8,] "314.2    "
> [9,] "3142     "
> [10,] "3.142e+04"
>
> formatC uses your system's C library printf {that's where the
> "C" comes from in 'formatC'} which seems to be
> broken or at least not performing as we think it should.
>
> On a "Windows 2003 Server" I have access to, I see the same
> wrong behavior as above.
>
> Martin Maechler, ETH Zurich
>
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>
>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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