// Singular Value Decomposition and associated matrix operations
//
// R. Perry, 10 Jan 2022

#include <iostream>
#include <cstdlib> // rand(), srand(), RAND_MAX, atoi(), getenv(), malloc(), exit()
#include <ctime>   // time()
#include "svd.h"

namespace Svd
{
// non-template functions:

// set srand() using time(0) or SRAND environment variable
unsigned int SRAND() {
  char *env = getenv( "SRAND"); unsigned int seed = 0; if( env) seed = atoi(env);
  if( seed == 0) seed = time(0);
  srand( seed); return seed;
}
// 0.0 <= drand < 1.0
double drand() {
  return rand()/(RAND_MAX+1.0);
}
// print error message and exit
void error( const char *msg) {
  std::cerr << msg << std::endl; exit(1);
}
// malloc with exit on error
void *emalloc( unsigned long size) {
  void *r = malloc(size); if( !r) { error( "svd: malloc() failed"); }  return r;
}

} // namespace Svd