#$
#$=head1 NAME
#$
#$mshelix - module containing allocate, deallocation, and extraction mshelix's
#$
#$=head1 SYNOPSIS
#$
#$C<call msallocate(msaa,nh,ns)>
#$
#$C<aa = onescale (msaa)>
#$
#$C<call msdeallocate(msaa)>
#$
#$
#$=head1 INPUT PARAMETERS
#$
#$=over 4
#$
#$=item msaa - type(msfilter)  
#$
#$      Multi-scale filter
#$
#$=item nh - integer    
#$
#$      Number of coefs in filter
#$
#$=item ns - integer    
#$
#$      Number of scales for the filter
#$
#$=item aa -  type(filter) 
#$
#$      A helix filter
#$
#$=back
#$
#$=head1 DESCRIPTION
#$
#$Module that controls creation, destruction, and conversion (helix)
#$for multi-scale filters.
#$
#$=head1 COMMENTS
#$
#$type(msfilter) :
#$
#$=over 4
#$
#$=item C<flt(nh)>  filter coefficients
#$
#$=item C<lag(nh,ns)>  filter lags
#$
#$=item C<mis(nd,ns)>  boundary conditions
#$
#$=back
#$
#$=head1 SEE ALSO
#$
#$L<helix>,L<nhelix>
#$
#$=head1 LIBRARY
#$
#$B<geef90>
#$
#$=cut
#$

module mshelix {                                # multiscale helix filter type
  use helix
  type msfilter {             
    real,    dimension( :),    pointer :: flt   # (nh) filter coefficients
    integer, dimension( :, :), pointer :: lag   # (nh,ns) filter (lags,scales)
    logical, dimension( :, :), pointer :: mis   # (nd,ns) boundary conditions
  }
contains
  subroutine msallocate( msaa, nh, ns) {
    type( msfilter)   :: msaa
    integer           :: nh, ns
    allocate( msaa%flt( nh), msaa%lag( nh, ns))
    msaa%flt = 0.;  nullify( msaa%mis)
    }
  subroutine msdeallocate( msaa) {
    type( msfilter) :: msaa
    deallocate( msaa%flt, msaa%lag)
    if( associated( msaa%mis)) deallocate( msaa%mis)
    }
  function onescale( i, msaa) result (aa) {      # Extract single-scale filter.
    integer, intent (in) :: i
    type( filter)        :: aa
    type( msfilter)      :: msaa
    aa%flt => msaa%flt
    aa%lag => msaa%lag( :, i)
    if( associated( msaa%mis)) 
	aa%mis => msaa%mis( :, i)
    else
        nullify( aa%mis)
    }
}