doc/eval: fix/review the section about SI prefixes and usage

In particular, prefer "prefix" to "postfix" as in the tool manuals, and
specify powers of 2 and 10 explicitly.

This is based on the commit:
commit 2bf794b69820273e2284d69e9b9c98f5b7136add
Author: Marcus Stollsteimer <sto.mar@web.de>
Date:   Mon Nov 19 21:39:20 2012 +0100
This commit is contained in:
Stefano Sabatini 2013-01-23 12:06:41 +01:00
parent ca1bc188f4
commit c89a8ee23d

View File

@ -209,55 +209,56 @@ In your C code, you can extend the list of unary and binary functions,
and define recognized constants, so that they are available for your and define recognized constants, so that they are available for your
expressions. expressions.
The evaluator also recognizes the International System number The evaluator also recognizes the International System unit prefixes.
postfixes. If 'i' is appended after the postfix, powers of 2 are used If 'i' is appended after the prefix, binary prefixes are used, which
instead of powers of 10. The 'B' postfix multiplies the value for 8, are based on powers of 1024 instead of powers of 1000.
and can be appended after another postfix or used alone. This allows The 'B' postfix multiplies the value by 8, and can be appended after a
using for example 'KB', 'MiB', 'G' and 'B' as postfix. unit prefix or used alone. This allows using for example 'KB', 'MiB',
'G' and 'B' as number postfix.
Follows the list of available International System postfixes, with The list of available International System prefixes follows, with
indication of the corresponding powers of 10 and of 2. indication of the corresponding powers of 10 and of 2.
@table @option @table @option
@item y @item y
-24 / -80 10^-24 / 2^-80
@item z @item z
-21 / -70 10^-21 / 2^-70
@item a @item a
-18 / -60 10^-18 / 2^-60
@item f @item f
-15 / -50 10^-15 / 2^-50
@item p @item p
-12 / -40 10^-12 / 2^-40
@item n @item n
-9 / -30 10^-9 / 2^-30
@item u @item u
-6 / -20 10^-6 / 2^-20
@item m @item m
-3 / -10 10^-3 / 2^-10
@item c @item c
-2 10^-2
@item d @item d
-1 10^-1
@item h @item h
2 10^2
@item k @item k
3 / 10 10^3 / 2^10
@item K @item K
3 / 10 10^3 / 2^10
@item M @item M
6 / 20 10^6 / 2^20
@item G @item G
9 / 30 10^9 / 2^30
@item T @item T
12 / 40 10^12 / 2^40
@item P @item P
15 / 40 10^15 / 2^40
@item E @item E
18 / 50 10^18 / 2^50
@item Z @item Z
21 / 60 10^21 / 2^60
@item Y @item Y
24 / 70 10^24 / 2^70
@end table @end table
@c man end @c man end