The :command:`specint_to_specint` tool subsets and/or rebins data in an existing :f-schema:`specint` file It accepts the following command-line arguments:
.. program:: specint_to_specint
.. option:: <specint_file_name_in> Name of input :f-schema:`specint` file.
.. option:: <specint_file_name_out> Name of output :f-schema:`specint` file.
.. option:: lam_min=<value> (optional) Subset to have a minimum wavelength of at least `<value>` (:math:`\angstrom`).
.. option:: lam_max=<value> (optional) Subset to have a maximum wavelength of at most `<value>` (:math:`\angstrom`).
.. option:: R=<value> (optional)
Rebin to have a uniform resolution :math:`\mathcal{R}` of `<value>`.
.. option:: dlam=<value> (optional) Rebin to have a uniform wavelength spacing :math:`\Delta \lambda` of `<value>` (:math:`\angstrom`).
.. option:: just=<L|R> (optional) Justify the new wavelength abscissa to the left (:code:`L`) or right (:code:`R`).