mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2025-10-31 13:10:19 -04:00
83 lines
2.6 KiB
C
83 lines
2.6 KiB
C
// normrnd.c
|
|
// functions to generate gaussian distributed numbers
|
|
//
|
|
// (c) 2016 - Nico Palermo, IV3NWV - Microtelecom Srl, Italy
|
|
//
|
|
// Credits to Andrea Montefusco - IW0HDV for his help on adapting the sources
|
|
// to OSs other than MS Windows
|
|
//
|
|
// ------------------------------------------------------------------------------
|
|
// This file is part of the qracodes project, a Forward Error Control
|
|
// encoding/decoding package based on Q-ary RA (Repeat and Accumulate) LDPC codes.
|
|
//
|
|
// qracodes is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
// qracodes is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with qracodes source distribution.
|
|
// If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
|
|
#include "normrnd.h"
|
|
|
|
#if _WIN32 // note the underscore: without it, it's not msdn official!
|
|
// Windows (x64 and x86)
|
|
#include <windows.h> // required only for GetTickCount(...)
|
|
#define K_RAND_MAX UINT_MAX
|
|
#elif _SVID_SOURCE || _XOPEN_SOURCE || __unix__ || (defined (__APPLE__) && defined(__MACH__)) /* POSIX or Unix or Apple */
|
|
#include <stdlib.h>
|
|
#define rand_s(x) (*x)=(unsigned int)lrand48() // returns unsigned integers in the range 0..0x7FFFFFFF
|
|
#define K_RAND_MAX 0x7FFFFFFF // that's the max number
|
|
// generated by lrand48
|
|
#else
|
|
#error "No good quality PRNG found"
|
|
#endif
|
|
|
|
|
|
// use MS rand_s(...) function
|
|
void normrnd_s(float *dst, int nitems, float mean, float stdev)
|
|
{
|
|
unsigned int r;
|
|
float phi=0, u=0;
|
|
int set = 0;
|
|
|
|
while (nitems--)
|
|
if (set==1) {
|
|
*dst++ = (float)sin(phi)*u*stdev+mean;
|
|
set = 0;
|
|
}
|
|
else {
|
|
rand_s((unsigned int*)&r); phi = (M_2PI/(1.0f+K_RAND_MAX))*r;
|
|
rand_s((unsigned int*)&r); u = (float)sqrt(-2.0f* log( (1.0f/(1.0f+K_RAND_MAX))*(1.0f+r) ) );
|
|
*dst++ = (float)cos(phi)*u*stdev+mean;
|
|
set=1;
|
|
}
|
|
}
|
|
|
|
/* NOT USED
|
|
// use MS rand() function
|
|
void normrnd(float *dst, int nitems, float mean, float stdev)
|
|
{
|
|
float phi=0, u=0;
|
|
int set = 0;
|
|
|
|
while (nitems--)
|
|
if (set==1) {
|
|
*dst++ = (float)sin(phi)*u*stdev+mean;
|
|
set = 0;
|
|
}
|
|
else {
|
|
phi = (M_2PI/(1.0f+RAND_MAX))*rand();
|
|
u = (float)sqrt(-2.0f* log( (1.0f/(1.0f+RAND_MAX))*(1.0f+rand()) ) );
|
|
*dst++ = (float)cos(phi)*u*stdev+mean;
|
|
set=1;
|
|
}
|
|
}
|
|
*/
|