module invint {                      # invint -- INVerse INTerpolation in 1-D.
  use lint1
  use tcai1
  use cgstep_mod
  use reg_solver
contains
  subroutine invint1( niter, coord, dd, o1, d1, aa, mm, eps) {
    integer,               intent (in)   :: niter               # iterations
    real,                  intent (in)   :: o1, d1, eps         # axis, scale
    real, dimension (:),   pointer       :: coord, aa           # aa is filter
    real, dimension (:),   intent (in)   :: dd                  # data
    real, dimension (:),   intent (out)  :: mm                  # model
    integer                              :: nreg                # size of A m
    nreg = size( aa) + size( mm)                                # transient

    call lint1_init( o1, d1, coord )                            # interpolation
    call tcai1_init( aa, size( mm))                             # filtering

    call solver_reg( lint1_lop, cgstep, tcai1_lop, nreg, mm, dd, niter, eps)
    call cgstep_close( )
    }
}