Warnings are an interesting idea. In principle, I have
absolutely no objections to StataCorp providing warnings
if they can
1. Provide a way of turning them off too. Large, complex datasets,
which means most of them, could otherwise be analysed only
with a permanent cacophonous chorus in the background.
2. Devise fairly consistent criteria for what kinds of warnings
are produced.
3. Be confident that this is more important as an extra feature
than filling other longstanding gaps in Stata. If Stata 11
doesn't include 3-D graphics, I will ... [Sorry, have to go now.]
Nick
[email protected]
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Austin
Nichols
Sent: 08 January 2008 17:15
To: [email protected]
Subject: Re: st: RE: RE: RE: statalist-digest V4 #2935 - strange world
Nick--
As usual, I agree with most of your points, but Allan raises a
different objection--he does not want Stata to stop treating (.) as
more than any finite number, or (.a) as more than (.), but only to
report that it is doing so when a calculation or comparison involves
missing values. I think that warning messages are a very good idea,
while changing Stata's logic is a very bad one. This behavior of
missing values seems to confuse enough people to justify a (small) set
of warnings for these kinds of cases. The trouble is, the warning
message would have to trap every -if- qualifier on every command,
which sounds like it could involve a lot of work. Maybe just
-generate- and -replace- would be a good start? In that case, you
would also want a warning message for a statement like
. gen hirep=rep78>3
On Jan 8, 2008 11:39 AM, Nick Cox <[email protected]> wrote:
> I am with StataCorp on this, not that they need my
> support.
<snip>
> Allan Reese
> ===========
>
> Others have pointed out that "if x>y" in Stata evaluates as True when
x
> is missing "."
>
> I've raised this before and had to accept as a feature of Stata that
"."
> is a big number and "computers do what you tell them, not what you
> want." Nevertheless, I remain of the opinion that it is
> counter-intuitive, logically incorrect, and undoubtedly leads to
> computer-assisted errors. Changing the operation of Stata now would
> inconvenience most current users, but it would not be inconsistent if
> the kernel were adapted to output a warning after such calculations
> "Missing values included - check your results".
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