Initial data for the exact solution subroutine d_smooth/u_exa.f:

3.		maximum temperature 'umax' in the center of the bar.
1.		steepening parameter 'alpha' for the initial profile.

The initial profile takes the form
	u = umax arctan(alpha sin(pi x/l)) / arctan(alpha)
hence for
	alpha = 0:		u(x,0) = umax sin(pi x/l)
	alpha = infinity:	u(x,0) = umax

Copyright 1996 Leon van Dommelen