# keyword: tridiagonal smoothing on 1-axis or 2-axis
subroutine leaky( distance, m1, n12, uu, vv )
integer i,                  m1, n12
real	distance	# input:  1. < distance < infinity
real	uu(m1,n12)	# data in  is the vector (uu( 1, i), i=1,n12)
real	vv(m1,n12)	# data out is the vector (vv( 1, i), i=1,n12)
real a, b, dc, side
temporary real vecin( n12), vecout( n12)
a  = - (1.-1./distance);	b = 1.+a*a; 	dc = b+a+a
a = a/dc;  	b = b/dc;	side = a + b
do i= 1,n12 { vecin(i) = uu(1,i)}
if( distance<=1.| n12==1) {call copy( n12, vecin, vecout)}
else			  {call tris( n12, side, a, b, a, side, vecin, vecout)}
do i= 1,n12  { vv(1,i) = vecout(i) }
return;	end