RE: st: doubt on the output format %w.dg

[Grace Jessie <gracejessie@hotmail.com>]

Nick,
Of course, I appreciate the programming of -format- very much. 
I  just want to learn more and better. 
It seems that there is not a simple rule which can tell us how the format %w.dg works.
Anyway, thank you very much!
 
Grace
 
> Date: Sat, 12 Mar 2011 16:28:38 +0000
> Subject: Re: st: doubt on the output format %w.dg
> From: njcoxstata@gmail.com
> To: statalist@hsphsun2.harvard.edu
> 
> The results are certainly not random. People would have noticed and
> complained long since if they were.
> 
> At this moment I am away from manuals and can not therefore check for
> further discussion in the manuals. A key point is that the precise
> algorithm is embedded in proprietary code. I don't recollect that a
> fully explicit verbal equivalent has ever been included in the
> manuals.
> 
> If you have ever tried to program a format that was adaptive to a
> unpredictable variety of inputs, you will appreciate the difficulty of
> doing that.
> 
> In my own programs I usually know what number of decimal places seems
> sensible and use an %f format.
> 
> Nick
> 
> 2011/3/12 Grace Jessie <gracejessie@hotmail.com>:
> > NIck,
> > I had read the -help format- file several times before I asked the question and the examples are all from that.
> > I can understand %f very well, but %g is another thing.
> > Does "with %g you give up most of the control and let Stata decide" in your reply mean the result for %g is random?
> > Or else, what I want to know is how Stata dicides it.
> > Additionally, in the Users' Guide, it is said that "The %w.0g format is a set of formatting rules that present
> > the values in as readable a fashion as possible without sacrificing precision. The g format changes
> > the number of decimal places displayed whenever it improves the readability of the current value."
> > And it takes the followings for example which puzzle me also.
> > . di %9.0g sqrt(2)
> > 1.414214
> > // The width of 1.414214 is 8. I think it should be 1.4142136 (with the width of 9) which gives less precision sacrifice.
> >
> > . di %11.0gc 23667902
> > 23667902
> > There are no commas. With regard to it, the explanation in the [D]Data Management is that "This number was too large for
> > Stata to insert commas and still respect the current width of 11." Why the current width is 11? It is 8 certainly, isn't it?
> > . di %12.0gc 23667902
> > 23,667,902
> > Together with the question in the first posting, I hope for any help.
> > Thank you.
> > Grace
> >
> >
> > ----------------------------------------
> >> Date: Sat, 12 Mar 2011 12:23:08 +0000
> >> Subject: Re: st: doubt on the output format %w.dg
> >> From: njcoxstata@gmail.com
> >> To: statalist@hsphsun2.harvard.edu
> >>
> >> -help format- is the place to start. I think the main thing is not to
> >> expect the rules for %g formats to be much like those for %f formats.
> >> With %f, you keep most of the control; with %g you give up most of the
> >> control and let Stata decide.
> >>
> >> Nick
> >>
> >> >> From: gracejessie@hotmail.com
> >>
> >> >> I can not understand the variables' output format %w.dg.
> >> >> How does Stata leave up to the format the number of digits to be displayed to the right of the decimal point if d equals 0 and not more than d digits will be displayed if d!=0.
> >> >> For example,
> >> >> What does "12.0g" mean?
> >> >> Why "di %12.0g 5231371222.139" or "di %12.1g 5231371222.139" equals "5231371222", not "5231371222.1"? (the width of "5231371222" is 10, not 12.)
> >> >> Why "di %12.0g 0.0000029394" equals "2.93940e-06", not "2.9394e-06"?
> 
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