Subject: adding floats. a peculiarity, and a proposal
From: Richard Fateman
Date: Fri, 1 Sep 2006 07:44:59 -0700
> -----Original Message-----
> From: Raymond Toy [mailto:raymond.toy at ericsson.com]
....>
> Not sure I like this. If I said 0.1d0, then I want 0.1d0.
> If I wanted an exact rational I would have said 1/10.
If you have an explicit marker "I want a double" that would make sense.
If you have a somewhat vaguer marker "I want to use decimal positional
notation,
(perhaps with an exponent e)" then what does that mean?
Does 0.1 or 0.1e0 mean 1/10 or does it mean
0.10000000000000000034694469519536141888238489627838134765625..... ?
I think that 1/10 is less confusing for the computationally naive; the
expert who
knows about floating point arithmetic can be told to use d. The person who
knows
only a little about floats is often confused anyway :)
> However, it would be useful to have, say, 0.1234567r0 mean
> the exact rational 1234567/100000000, without me having to
> write the denominator explicitly.
This is possible too: how many exponent markers do we want? eEdDsSbBrR?
RJF