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c++11: Simplify random generation code using C++11.

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* src/misc/random.cc, src/misc/random.hh (srand, drand, mrand, rrand,
barand): Simplify using <random> from C++11.
(nrand, bmrand, prand): Remove these unused functions.
* src/tgbaalgos/randomgraph.cc: Adjust the use of barand.
* configure.ac: Do not check for srand48 and drand48.
This commit is contained in:
Alexandre Duret-Lutz 2013-12-18 23:42:25 +01:00
parent 7480470760
commit c64503fb33
4 changed files with 18 additions and 147 deletions
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102
src/misc/random.cc
View file

@ -21,121 +21,43 @@
// along with this program. If not, see <http://www.gnu.org/licenses/>.
#include "config.h"
#include "_config.h"
#include "random.hh"
#include <cstdlib>
namespace spot
{
std::mt19937 gen;
void
srand(unsigned int seed)
{
#if SPOT_HAVE_SRAND48 && SPOT_HAVE_DRAND48
::srand48(seed);
#else
::srand(seed);
#endif
gen.seed(seed);
}
double
drand()
{
#if SPOT_HAVE_SRAND48 && SPOT_HAVE_DRAND48
return ::drand48();
#else
double r = ::rand();
return r / (1.0 + RAND_MAX);
#endif
return
std::generate_canonical<double,
std::numeric_limits<double>::digits>(gen);
}
int
mrand(int max)
{
return static_cast<int>(max * drand());
std::uniform_int_distribution<> dis(0, max - 1);
return dis(gen);
}
int
rrand(int min, int max)
{
return min + static_cast<int>((max - min + 1) * drand());
}
double
nrand()
{
const double r = drand();
const double lim = 1.e-20;
if (r < lim)
return -1./lim;
if (r > 1.0 - lim)
return 1./lim;
double t;
if (r < 0.5)
t = sqrt(-2.0 * log(r));
else
t = sqrt(-2.0 * log(1.0 - r));
const double p0 = 0.322232431088;
const double p1 = 1.0;
const double p2 = 0.342242088547;
const double p3 = 0.204231210245e-1;
const double p4 = 0.453642210148e-4;
const double q0 = 0.099348462606;
const double q1 = 0.588581570495;
const double q2 = 0.531103462366;
const double q3 = 0.103537752850;
const double q4 = 0.385607006340e-2;
const double p = p0 + t * (p1 + t * (p2 + t * (p3 + t * p4)));
const double q = q0 + t * (q1 + t * (q2 + t * (q3 + t * q4)));
if (r < 0.5)
return (p / q) - t;
else
return t - (p / q);
}
double
bmrand()
{
static double next;
static bool has_next = false;
if (has_next)
{
has_next = false;
return next;
}
double x;
double y;
double r;
do
{
x = 2.0 * drand() - 1.0;
y = 2.0 * drand() - 1.0;
r = x * x + y * y;
}
while (r >= 1.0 || r == 0.0);
r = sqrt(-2 * log(r) / r);
next = y * r;
has_next = true;
return x * r;
std::uniform_int_distribution<> dis(min, max);
return dis(gen);
}
int
prand(double p)
barand::rand()
{
double s = 0.0;
long x = 0;
while (s < p)
{
s -= log(1.0 - drand());
++x;
}
return x - 1;
return (*this)(gen);
}
}