The commands `EXTINCT/LONG` followed by `RESPONSE/FILTER`
or by `INTEGRATE/LONG` and `RESPONSE/LONG` permit a
one-dimensional response curve `response.bdf` to be obtained from
the extracted (*e.g.*, via `EXTRACT/LONG` or `EXTRACT/AVERAGE`)
and wavelength calibrated spectrum of a standard star.

The command `RESPONSE/FILTER` divides the standard star spectrum
by the flux table values and uses median and smooth filterings
(parameters `FILTMED` and `FILTSMO`) to
smooth the instrumental response function.

The command `INTEGRATE/LONG` also performs a division of the
standard star spectrum by the flux table but generates an table
of response values at a wavelength step equal to the one of the
flux table. The command `RESPONSE/LONG` interpolates these
values using a polynomial or spline interpolation scheme.

This response curve can be applied to a one- or two-dimensional
extracted, wavelength calibrated and extinction corrected
(`EXTINCTION/LONG`) spectrum by the command `CALIBRATE/FLUX`.

Verification commands include `PLOT/FLUX` to visualize the
standard star reference flux table and `PLOT/RESPONSE` to
vizualize the final instrumental response
function.