Hmmm - the odd behaviour with negative numbers is not unique to SBASIC.
I've just tried it with QBASIC in NT and it does exactly the same.
I'd be interested to read the ISO or ANSI standard on this for the
justification. Curiously, the 68040 provides two instructions for
getting an integer from a float: FINT allows user specified rounding,
e.g. 'round-to-nearest', while FINTRZ always does 'round-to-zero'. I
still can't see the usefulness in having INT(-3.01)=-4 though. Any
mathematicians care to comment?
Ian.
> -----Original Message-----
> From: pjwitte
> Sent: 19 June 2001 16:25
> To: ql-users
> Cc: pjwitte
> Subject: Re: [ql-users] NEXT in FOR-loop
>
>
> > >Only guessing because I can't try this until I get home, but when n
> > >reaches the value 2.9999.... (the nearest it'll get to 3.00
> because
> > >0.01 is not represented exactly internally [that would need an
> infinite
> > >number of bits]), then PRINT n will round up to 3, whereas INT(n)
> will
> > >return the correct answer (2) which needs no rounding and therefore
> > >prints as 2.
> >
> > Print returns 3 because of rounding of the QL float precision of >9
> digits
> > to 7 digits available for printing. INT operates directly from QL
> float
> > format and will therefore give the right result: 2. This will again
> be
> > rounded to 7 digitsby print but obviously 2.0000000 = 2.000000 so
> nothing
> > will change.
>
> SMSQ/E, and I think Qdos also, operates with (at least) four
> different rounding schemes:
>
> 1) PRINT 2.999999 prints 3 (6 decimals)
> This affects the display only, not the maths
>
> 2) x$ = x: PRINT x$ prints 2.999999, but
> x = 2.9999999: x$ = x: PRINT x$ prints 3! (7 d)
> This rounding takes place during conversion to ascii
>
> x = 2.99999: PRINT x prints the expected 2.99999 (5 d)
> 3) PRINT INT(x) prints 2
> 4) x% = x: PRINT x% prints 3
>
> x = -2.99999: PRINT x prints the expected -2.99999
> 3) PRINT INT(x) prints -3
> 4) x% = x: PRINT x% prints -3
>
> Thus INT truncates to next _smaller_ integer, coercion rounds to
> _nearest_ integer. (For integers, method 4 is thus more precise.)
>
>
> Per
>
>
>
>
>
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