def load_data(self, idx):
        """Load the internal data of all sequences.  Load from file if the
        corresponding disk flag is activated, otherwise load from RAM."""
        for name in self:
            ndim = getattr(self, '_%s_ndim' % name)
            diskflag = getattr(self, '_%s_diskflag' % name)
            ramflag = getattr(self, '_%s_ramflag' % name)
            if diskflag:
                file_ = getattr(self, '_%s_file' % name)
                length_tot = 1
                shape = []
                for jdx in range(ndim):
                    length = getattr(self, '_%s_length_%s' % (name, jdx))
                    length_tot *= length
                    shape.append(length)
                raw = file_.read(length_tot*8)
                values = struct.unpack(length_tot*'d', raw)
                if ndim:
                    values = numpy.array(values).reshape(shape)
                else:
                    values = values[0]
            elif ramflag:
                array = getattr(self, '_%s_array' % name)
                values = array[idx]
            if diskflag or ramflag:
                if ndim == 0:
                    setattr(self, name, values)
                else:
                    getattr(self, name)[:] = values
Load the internal data of all sequences.  Load from file if the
        corresponding disk flag is activated, otherwise load from RAM.