Allan--
This response I utterly fail to understand--I have seconded your call
for a warning message, several times (is the 3rd time still
seconding?), while pointing out that no software can prevent people
from making errors (hence "some casualties are unavoidable" under any
design). Software that guesses at what you mean is poorly designed,
but software that announces the direct implications of what you coded
is just offering friendly guidance.
I have written a draft version of a command that incorporates warning
messages for -gen- and -replace- and -egen- but such a command will
not protect users who have a condition with implications for a later
-gen- or -replace- or -egen- e.g.
_pctile y if x>42, nq(100)
g hi_x_yp5=r(r5)
Writing a more general warning system would be up to Statacorp, since
it would need to take account of missing values in locals/globals and
scalars as well, which sounds like a major undertaking.
On Jan 10, 2008 6:09 AM, Allan Reese (Cefas) <[email protected]> wrote:
> > Austin Nichols asks:
> > ... on the issue of how often a qualifier such as "if x > 42"
> > can lead to an incorrect analysis, I think there are many dangers of
> > this sort, and many users fall prey to them. Users of other software
> > fall under other wheels, and it seems that some casualties are unavoidable.
>
> Is an attitude I refute utterly and smacks horribly of Harry Lime's soliloquy on the Riesenrad (big wheel - Third Man):
> "If I offered you �20,000 for every dot that stopped - would you really, old man, tell me to keep my money? Or would you calculate how many dots you could afford to spare?...Free of Income Tax, old man...".
>
> Also, the Herald of Free Enterprise disaster started with management who declined to add a safety alarm when directly asked.
>
> Nick has reminded me I made the same suggestion (warning message) four years ago. As in the case of the Herald, current law allows software vendors to deny any responsibility for malfunction or consequential loss. Some time, this position will be challenged and changed.
>
> Allan
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