//  Location:
//
//    http://people.sc.fsu.edu/~jburkardt/freefem_src/io_test/io_test.edp
//
//  Discussion:
//
//    This example illustrates how FreeFem++ can read and write text files.
//
//    Note that a file containing a vector must have an initial record
//    listing the number of elements in the file.  Thus, the file "input.txt"
//    has the form:
//
//    11
//    0  1  2  3  4
//    5  6  7  8  9
//    10
//
//  Licensing:
//
//    This code is distributed under the MIT license.
//
//  Modified:
//
//    04 February 2015
//
//  Reference:
//
//    John Chrispell, Jason Howell,
//    Finite Element Approximation of Partial Differential Equations
//    Using FreeFem++, or, How I Learned to Stop Worrying and Love
//    Numerical Analysis.
//
//    Frederic Hecht,
//    New development in FreeFem++,
//    Journal of Numerical Mathematics,
//    Volume 20, Number 3-4, 2012, pages 251-265.
//
  cout << "\n";
  cout << "io_test:\n";
  cout << "  FreeFem++ version\n";
  cout << "  Read values from the file 'input.txt'\n";
  cout << "  Write their square roots to the file 'output.txt'\n";
//
//  Declare IN to be an input unit.
//
ifstream in ( "input.txt" );
//
//  Declare U to be a real array indexed by integers.
//
real[int] u(11);
//
//  Read data from "input.txt" into U.
//
in >> u;
//
//  Declare V to be a real array indexed by integers.
//
real[int] v(11);
//
//  Manipulate the data and print it to convince us it got here.
//
for ( int j = 0; j < 11; j++ )
{
  v[j] = sqrt ( u[j] );
  cout << "  " << u[j] 
       << "  " << v[j] << "\n";
}
//
//  Declare OUT to be an output unit.
//
ofstream out ( "output.txt" );
//
//  Write V to the output unit.
//
out << v;
//
//  Terminate.
//
cout << "\n";
cout << "io_test\n";
cout << "  Normal end of execution.\n";

exit ( 0 );