'transform observation to the domain of the density
uses shrink and shift attribute which are set in fit to stay'

def _transform(self, x):

    domain = self.polys[0].domain
    ilen = (domain[1] - domain[0])
    shift = (self.shift - ((domain[0] / self.shrink) / ilen))
    shrink = (self.shrink * ilen)
    return ((x - shift) * shrink)
