elphyio.py 文件源码

def load_encoded_spikes(self, episode, evt_channel, identifier):
        """
        Return times stored as a 4-bytes integer
        in the specified spike channel.
        NB: it is meant for Blackrock-type, having an additional byte for each event time as spike sorting label.
            These additiona bytes are appended trailing the times.
        """
        # to load the requested spikes for the specified episode and event channel:
        # get all the elphy blocks having as identifier 'RSPK' (or whatever)
        all_rspk_blocks = [k for k in self.blocks if k.identifier == identifier]
        rspk_block = all_rspk_blocks[episode-1]
        # RDATA(h?dI) REVT(NbVeV:I, NbEv:256I ... spike data are 4byte integers
        rspk_header = 4*( rspk_block.size - rspk_block.data_size-2 + len(rspk_block.n_events))
        pre_events = np.sum(rspk_block.n_events[0:evt_channel-1], dtype=int, axis=0)
        # the real start is after header, preceeding events (which are 4byte) and preceeding labels (1byte)
        start = rspk_header + (4*pre_events) + pre_events
        end = start + 4*rspk_block.n_events[evt_channel-1]
        raw = self.load_bytes( [rspk_block], dtype='<i1', start=start, end=end, expected_size=rspk_block.size )
        # re-encoding after reading byte by byte
        res = np.frombuffer(raw[0:(4*rspk_block.n_events[evt_channel-1])], dtype='<i4')
        res.sort() # sometimes timings are not sorted
        #print "load_encoded_data() - spikes:",res
        return res