Commit fa9e2734 authored by Tim Peters's avatar Tim Peters

Clarification in the fp appendix suggested on c.l.py by Michael Chermside.

Also replaced a *star* style emphasis in the Representation Error section
with an \emph{} thingie.
parent 4157dd5a
...@@ -4180,7 +4180,8 @@ turns out that's enough (on most machines) so that ...@@ -4180,7 +4180,8 @@ turns out that's enough (on most machines) so that
Note that this is in the very nature of binary floating-point: this is Note that this is in the very nature of binary floating-point: this is
not a bug in Python, it is not a bug in your code either, and you'll not a bug in Python, it is not a bug in your code either, and you'll
see the same kind of thing in all languages that support your see the same kind of thing in all languages that support your
hardware's floating-point arithmetic. hardware's floating-point arithmetic (although some languages may
not \emph{display} the difference by default, or in all output modes).
Python's builtin \function{str()} function produces only 12 Python's builtin \function{str()} function produces only 12
significant digits, and you may wish to use that instead. It's significant digits, and you may wish to use that instead. It's
...@@ -4326,7 +4327,7 @@ precision is that over 2**56, or ...@@ -4326,7 +4327,7 @@ precision is that over 2**56, or
Note that since we rounded up, this is actually a little bit larger than Note that since we rounded up, this is actually a little bit larger than
1/10; if we had not rounded up, the quotient would have been a little 1/10; if we had not rounded up, the quotient would have been a little
bit smaller than 1/10. But in no case can it be *exactly* 1/10! bit smaller than 1/10. But in no case can it be \emph{exactly} 1/10!
So the computer never ``sees'' 1/10: what it sees is the exact So the computer never ``sees'' 1/10: what it sees is the exact
fraction given above, the best 754 double approximation it can get: fraction given above, the best 754 double approximation it can get:
......
...@@ -71,6 +71,7 @@ Brad Chapman ...@@ -71,6 +71,7 @@ Brad Chapman
Mitch Chapman Mitch Chapman
David Chaum David Chaum
Nicolas Chauvat Nicolas Chauvat
Michael Chermside
Albert Chin-A-Young Albert Chin-A-Young
Tom Christiansen Tom Christiansen
Vadim Chugunov Vadim Chugunov
......
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