Assign all self.merge_values to the self._mergeMatrix
        Get the position/intensity of a value

def add(self, point, value):
        """
        Assign all self.merge_values to the self._mergeMatrix
        Get the position/intensity of a value
        """
        # check range
        for p, r in zip(point, self.range):
            if p < r[0] or p > r[1]:
                return
        # check nan
        if isnan(value):
            return

        refs = self.opts['references']
        # for all neighbour points (1, if antialiasting=False):
        for position, intensity in self.sortMethod.getPositionsIntensities(
                point):
            position = tuple(position)
            if self.mean is not None:
                old_value = self.values[position]
                if not np.isnan(old_value):
                    anz_values = self.density[position]
                    mean = old_value + intensity * (
                        ((value - old_value) / (anz_values + intensity)))
                    self.mean[position] = mean

                    if self.variance is not None:
                        self.variance[
                            position] += (abs(value - mean) / (
                                anz_values + intensity))

            if self.mergeMethod(self.values, position, intensity, value):
                for a in refs:
                    a.mergeMethod(a, position, intensity, value)
            if self.density is not None:
                self.density[position] += intensity