module unwrap {
	use cgstep_mod
	use igrad2
	use solver_smp_mod
contains
	subroutine makedata( z, n1,n2, rt ) {
	integer  i, j,           n1,n2
	real                 rt( n1,n2,2)
	complex               z( n1,n2  ),             a,b,c
	rt = 0.
	do i= 1, n1-1 {
	do j= 1, n2-1 {
        	a =  z(i  ,j  )        
        	c =  z(i+1,j  );     rt(i,j,1) =  aimag( clog( c * conjg( a) ) )
        	b =  z(i,  j+1);     rt(i,j,2) =  aimag( clog( b * conjg( a) ) )
        	}}
	}
	# Phase unwraper.   Starting from phase hh, improve it.
	subroutine unwraper( zz, hh, niter) {
	integer  n1,n2,              niter
	complex              zz(:,:)
	real                 hh(:)
	real, allocatable ::  rt(:)
	n1 = size( zz, 1) 
	n2 = size( zz, 2)
	allocate( rt( n1*n2*2))
	call makedata( zz,n1,n2, rt)
	call igrad2_init(  n1,n2)
	call solver_smp( m=hh, d=rt, Fop=igrad2_lop, stepper=cgstep, niter=niter, m0=hh)
	call cgstep_close ()
	deallocate( rt)
	}
}