def to_json(self, path, points=50, meta=None):
        """
        Write the results of the fit to a json file at `path`.

        `points` will define the length of the `fit` array.

        If `meta` is given, a `meta` key be added with the given value.

        The json object has the form

            #!text
            {
                'data': [ [x1, y1], [x2, y2], ... ],
                'fit': [ [x1, y1], [x2, y2], ... ],
                'meta': meta
            }
        """
        pointspace = self.pointspace(num=points)
        fit_points = numpy.dstack(pointspace['fit'])[0]
        data_points = numpy.dstack(pointspace['data'])[0]

        fit = [ [ point[0],  point[1] ] for point in fit_points ]
        data = [ [ point[0],  point[1] ] for point in data_points ]

        obj = {'data': data, 'fit': fit}
        if meta: obj['meta'] = meta

        f = open(path, 'w')
        json.dump(obj, f)
        f.close