root/campo-sirio
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Corretta gestione arrotondamenti usando i long double

Browse Source 
git-svn-id: svn://10.65.10.50/trunk@2201 c028cbd2-c16b-5b4b-a496-9718f37d4682
This commit is contained in:
guy 1995-11-23 14:20:38 +00:00
parent 13913bf186
commit 4d2fb08b25
1 changed files with 21 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
include/real.cpp
View File

@ -149,6 +149,23 @@ char *real::string (
return __string;
}
// Childish algorithm faster and more accurate than powl(10.0, pow)
HIDDEN long double ipow10(int pow)
{
long double n = 1.0;
if (pow > 0)
{
for (int i = pow; i > 0; i--)
n *= 10.0;
}
else
{
for (int i = pow; i < 0; i++)
n *= 0.1;
}
return n;
}
// @mfunc real& | real | round | Arrotonda al numero di decimali passati
real& real::round (
int prec) // @parm Numero di decimali a cui arrotondare il numero (default 0)
@ -161,8 +178,8 @@ real& real::round (
{
long double p = 1.0;
if (prec != 0)
{
p = powl (10.0, prec);
{
p = ipow10(prec);
_dec *= p;
}
_dec = floorl(_dec + 0.5);
@ -177,7 +194,7 @@ real& real::ceil (int prec)
long double p = 1.0;
if (prec != 0)
{
p = powl(10.0, prec);
p = ipow10(prec);
_dec *= p;
}
_dec = ceill(_dec);
@ -192,7 +209,7 @@ real& real::trunc(int prec)
long double p = 1.0;
if (prec != 0)
{
p = powl(10.0, prec);
p = ipow10(prec);
_dec *= p;
}
_dec = floorl(_dec);