text: #ifndef STDINC_H
  #define STDINC_H
  
  // Standard inclusion of various system files. 
  
  #ifndef NOMPI
  #include <mpi.h>
  #endif
  
  #include <iostream>
  #include <sstream>
  #include <fstream>
  #include <cstdlib>
  #include <cmath>
  #include <cstring>
  #include <unistd.h>
  
  using namespace std;
  typedef double real;
  typedef real (*real2)[3];	// 2-d array: "real2 x" = "real (*x)[3]"
  
  #include "vec.h"		// 3-d vector type
  
  #ifndef DEBUG
  #define DEBUG 0
  #endif
  
  #ifndef NN
      #define NN 2		// conditional nearest-neighbor computation
  #endif				// on GPU: not fully tested
  
  #define _INFINITY_ 1.0e300
  #define _TINY_	   (pow(2.0, -52))	  // double limit on powers of 2
  
  #define VERY_LARGE_INTEGER (1<<30)	  // assume we are working with
  					  // standard 4-byte integers, but
  					  // also want -(this) to be legal
  #define LOW_PRECISION	 3
  #define STD_PRECISION	 6
  #define INT_PRECISION	10
  #define HIGH_PRECISION	15
  
  #define PRI(n) for (int __k = 0; __k < n; __k++) cout << " "
  #define PR(x)  cout << #x << " = " << x << " "
  #define PRC(x) cout << #x << " = " << x << ",  "
  #define PRL(x) cout << #x << " = " << x << endl << flush
  #define PRLL(x) cout << #x << " = " << x << endl << endl << flush
  
  //#define PRC(r,x) cout << r << ": " << #x << " = " << x << ",  " << flush
  //#define PRL(r,x) cout << r << ": " << #x << " = " << x << endl << flush
  
  //-----------------------------------------------------------------------------
  //  pos_angle  --  recasts an angular variable into the range [0, TWO_PI)
  //  sym_angle  --  recasts an angular variable into the range [-PI, PI)
  //-----------------------------------------------------------------------------
  
  #define  pos_angle(phi)    ((phi) - 2*M_PI * floor((phi)/(2*M_PI)))
  #define  sym_angle(phi)    ((phi) - 2*M_PI * floor(((phi)+M_PI)/(2*M_PI)))
  #define  sign(x)	   ((x > 0 ? 1 : (x < 0 ? -1 : 0)))
  
  // Functions in util.cc:
  
  real get_elapsed_time();
  void get_cpu_time(real& user_time, real& system_time);
  void warning(const char *s);
  void err_exit(const char *s);
  
  int srandinter(int seed, int iter);
  int getrandinter();
  real randinter(real a = 0, real b = 1);
  
  #endif
  
  