Use simple quadratic interpolation
to model line wings on fine grid.
Use inverse quadratic (Lorentzian shape)
interpolation to model line wings on fine grid
The main use of this flag is to investigate whether the
form of polynomial used to interpolate wide-mesh calculations to
the fine grid significantly affects the results. The order of polynomial
is hard-wired by the dimension 3 in arrays
ABSWID, CNTWID (see Memory Size) and not
something that is easily altered, so inverting it is about the only option.
A second use is that the RFM may flip from inverse quadratic to quadratic
for a small change in input parameters, giving significantly different spectra.
The clue is that the difference between two spectra has a sinusoidal shape
in a 1 cm-1 internval
with a zero-crossing at 0.5 cm-1. This flag
forces quadratic throughout which, although not as accurate, at least enforces