lpogoda <lpogoda@HOTMAIL.COM> wrote:
>50 year old literary allusions aside, you seem to be saying
>that a low proportion of practicing programmers have
>read the documentation, and by implication very few
>know what they're doing. That is as may be,
>what doesn't follow is that it's the language that's to
>blame for the situation.
It's not the language, it's the documentation.
In version 5, the documentation for NODUPLICATES stated with "checks
for and eliminates duplicate records". That's pretty clear and
The next paragraph describes how the process is performed, and says
"This option causes PROC SORT to compare all variable values for each
observation to the previous one written to the output data set." That
is misleading, as it implies that each output observation is compared
with the previous output observation. That's not how it works, as the
version 9 documentaiton makes clear (and there's a new system option,
SORTDUP, to make it work in the way a reasonable reader would think it
ought to work).
But the version 5 documentation didn't make that clear, and the only
way to find out how it actually worked was to use a "properly"
constucted set of input data. I had used NODUPLICATES for years before
I (accidentally) encountered the problem.
Manager, Technical Development
Metrics Department, First Health
West Sacramento, California USA