utils_1.h

关于Q元LDPC码的C++仿真程序

#ifndef UTILS_1
#define UTILS_1

#include <math.h>
#include <iostream.h>
#include <string.h>


/************************************************************************
 *
 * Cout
 *
 ************************************************************************/

class reportbuf : public streambuf
{
public:
   int IsDirectedToErr;  // BOOLEAN has not yet been defined at this stage of compilation
   FILE *fp;
public:
   reportbuf(): IsDirectedToErr(/*FALSE*/ 0), fp(NULL)
   { }

   void OpenFile(char *FileName)
   {
      // Make lowercase copy of FileName
      char buffer[1000];
      int i;
      for (i = 0; FileName[i] != '\0'; i++) buffer[i] = tolower(FileName[i]);
      buffer[i] = '\0';

      // If Filename is "err"
      if (strcmp(buffer, "err") == 0)
         IsDirectedToErr = /*TRUE*/ 1;
      else
         fp = fopen(FileName, "w");
   }

   virtual int overflow( int nCh ) 
   {
      if (!IsDirectedToErr)
      {
         if (fp == NULL)
         {
            printf("Reportbuf::overflow:  file not opened\n");
            exit(1);
         }

         putchar(nCh);
         fputc(nCh, fp);

         fflush(fp);
      }
      else
      {
         fputc(nCh, stderr);
      }

      return 0;
   }

   virtual int underflow()
   {
      if (!IsDirectedToErr)
         fflush(fp);

      return 0;
   }

   ~reportbuf()
   {
      if (!IsDirectedToErr)
         fclose(fp);
   }

} ;

extern ostream ReportOut;
extern reportbuf ReportBuf;
#define cout ReportOut


/************************************************************************
 *
 * Definitions
 *
 ************************************************************************/

#define INF             1e10
#define EPSILON         1e-10

#define TRUE   1
#define FALSE  0

typedef unsigned char BYTE;
typedef unsigned char BOOLEAN;


#define MAX_Q 	64  // Maximum allowed Q   (to be freely modified)


/************************************************************************
 *
 * Functions
 *
 ************************************************************************/


ifstream &operator>>(ifstream &file, double &d);
ifstream &operator>>(ifstream &file, int &num);
int uniform_random(int p_max);


inline double LLR(double x)
{
   return log((1-x)/x);
}



inline int max(int x, int y)
{
   return (x > y) ? x : y;
}



inline double max(double x, double y)
{
   return (x > y) ? x : y;
}



inline double mylog(double x)
{
   return (x != 0) ? log(x) : -INF;
}


inline int SumBits(BYTE b)
{
   int sum = 0;
   for(; b != 0; b >>= 1)
      sum += b & 1;

   return sum;
}


inline int XORBits(BYTE b)
{
   int sum = 0;
   for(; b != 0; b >>= 1)
      sum ^= b & 1;

   return sum;
}



inline int SumBitsLong(long l)
{
   int sum = 0;
   for(; l != 0; l >>= 1)
      sum += l & 1;

   return sum;
}


inline double log2(double x)
{
   if (x > 0)
      return log(x)/log(2.);
   else
      return -INF;
}




inline int Intlog2(int x)
{
   int acc = 0;

   while (x > 1)
   {
      x >>= 1;
      acc += 1;
   }

   return acc;
}


inline BOOLEAN IsPowerOfTwo(int num)
{
   BOOLEAN Reply = TRUE;

   for (int i = num; i > 2; i = i / 2)
   {
      if ((i % 2) != 0)
      {
         Reply = FALSE;
         break;
      }
   }

   return Reply;
}





inline BOOLEAN isnumber(char c)
{
   return (('0' <= c) && (c <= '9'));
}



inline double mod(double x, double y)
{
   return x - floor(x / y) * y;
}



inline double min_double(double x, double y)
{
   return (x < y) ? x : y;
}



/************************************************************************
 *
 * Portability include file
 *
 ************************************************************************/

#include "Portability.h"

#endif