Task

Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.

The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.

For example, considering:

   x = {1, 2, 3, 1e11};
   y = {1, 1.4142135623730951, 1.7320508075688772, 316227.76601683791}; 
                                                          /* sqrt(x) */
   xprecision = 3;
   yprecision = 5;

The file should look like:

   1    1
   2    1.4142
   3    1.7321
   1e+011   3.1623e+005

This task is intended as a subtask for Measure relative performance of sorting algorithms implementations.




template<class InputIterator, class InputIterator2>
void writedat(const char* filename,
              InputIterator xbegin, InputIterator xend,
              InputIterator2 ybegin, InputIterator2 yend,
              int xprecision=3, int yprecision=5)
{
  std::ofstream f;
  f.exceptions(std::ofstream::failbit | std::ofstream::badbit);
  f.open(filename);
  for ( ; xbegin != xend and ybegin != yend; ++xbegin, ++ybegin)
    f << std::setprecision(xprecision) << *xbegin << '\t'
      << std::setprecision(yprecision) << *ybegin << '\n';
}