function y = ascent ( h )

%% ASCENT reports the height of the ascending climbers.
%
%  H is the time, in hours. 
%  0 <= H <= 24;
%
%  Y is the height.
%  0 <= Y <= 10000.
%
  hmin = 0.0;
  hmax = 24.0;

  h2 = h;
  h2 = max ( h2, hmin );
  h2 = min ( h2, hmax );

  scale = hmax / 9.0 + besselj ( 2, hmax );

  y = ( 10000.0 / scale ) * ( h2 / 9.0 + besselj ( 2, h2 ) );

  return
end
