Hi everyone!

Sorry for taking an already overlong discussion thread slightly off- 
topic, but ...

> quote:
> No doubt, 7.0 is integer in math. But if people can write 7 why  
> people need to write 7.0 (I do not see any reason to do this).
> endquote

> What is true in mathematics is not necessarily true in R.

... am I the only one who thinks that the integer 7 is something  
entirely different from the real number 7.0? (The latter most likely  
being an equivalence class of sequences of rational numbers, but that  
depends on your axiomatisation of real numbers.) Integers can be  
embedded in the set of real numbers, but that doesn't make them the  
same mathematically.

So the original complaint should really have said that is.integer()  
doesn't do what a naive user (i.e. someone without a background in  
computer science or maths) might expect it to do. :-)

That said, I've fallen into the same trap more than once, and  
painfully, myself (often in connection with MySQL).


Best wishes, and with a tiny grain of salt,
Stefan Evert

[ stefan.evert@uos.de | http://purl.org/stefan.evert ]




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