function u0 = tumor_ic ( x )

%*****************************************************************************80
%
%% tumor_ic() sets the initial condition for the tumor PDE.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    29 January 2021
%
%  Author:
%
%    Original version by Chiara Villa.
%    Modifications by John Burkardt
%
%  Input:
%
%    real X, the spatial coordinate.
%
%  Output:
%
%    real U0(2), the initial condition for the solution at X.
%
  c0 = cos ( 0.5 * pi * x );
  if ( x < 1.0 )
    n0 = 0.0;
  else
    n0 = 1.0;
  end

  u0 = [ c0; n0 ];

  return
end

