Specify direction = -1 to "flip" the goalposts. In this case, the fraction from the upper to the lower goalpost is
measured.
The goalposts equations are:
$$ (x - GP_{low})/(GP_{high} - GP_{low}) $$
and for a negative directionality indicator:
$$ (x - GP_{high})/(GP_{low} - GP_{high}) $$
This function also supports parameter specification in iMeta for the Normalise.coin() method.
To do this, add columns:
goalpost_lower: the lower goalpost
goalpost_upper: the upper goalpost
goalpost_scale: the scaling parameter
goalpost_trunc2posts: corresponds to the trunc2posts argument
to the iMeta table. Then set f_n_para = "use_iMeta" within the
global_specs list. See also examples in the normalisation vignette.