def infer_x(self, y):
        """Infer probable x from input y

        @param y  the desired output for infered x.
        """
        assert len(y) == self.fmodel.dim_y, "Wrong dimension for y. Expected %i, got %i" % (self.fmodel.dim_y, len(y))
        self.goal = np.array(y)
Infer probable x from input y

        @param y  the desired output for infered x.