# 	Convolve and correlate (adjoint convolve).
#
subroutine contran( adj, add, nx, xx, nb, bb, yy)
integer ix, ib, ny, adj, add, nx,     nb
real	xx(nx)			# input signal
real	bb(nb)			# filter      (or output crosscorrelation)
real	yy(nx+nb-1)		# filtered signal (or second input signal)
ny = nx + nb - 1		# length of filtered signal
call adjnull(       adj, add,         bb, nb, yy, ny)
do ib= 1, nb {
do ix= 1, nx {
	if( adj == 0 )
		yy( ib+ix-1) = yy( ib+ix-1) + xx( ix) * bb(ib)
	else
		bb( ib)      = bb( ib)      + xx( ix) * yy( ib+ix-1)
	}}
return;	end