def create_dataset(self, group, chunk_size):
"""Initialize the features subgoup."""
group.attrs['format'] = self.dformat
super().create_dataset(group, self.dtype, self.dim, chunk_size)
# attribute declared outside init is not safe. Used because
# Times.create_dataset need it
self.nb_per_chunk = _nb_per_chunk(self.dtype.itemsize,
self.dim, chunk_size)
def create_dataset(self, group, chunk_size):
"""Initializes sparse specific datasets."""
group.attrs['format'] = self.dformat
group.attrs['dim'] = self.dim
# for storing sparse data we don't use the self.nb_per_chunk,
# which is only used by the Writer to determine times chunking.
per_chunk = _nb_per_chunk(self.dtype.itemsize, 1, chunk_size)
group.create_dataset('coordinates', (0, 2), dtype=np.float64,
chunks=(per_chunk, 2), maxshape=(None, 2))
group.create_dataset(self.name, (0,), dtype=self.dtype,
chunks=(per_chunk,), maxshape=(None,))
dtype = np.int64
chunks = (_nb_per_chunk(np.dtype(dtype).itemsize, 1, chunk_size),)
group.create_dataset('frames', (0,), dtype=dtype,
chunks=chunks, maxshape=(None,))
# Needed by Times.create_dataset
self.nb_per_chunk = _nb_per_chunk(self.dtype.itemsize,
int(round(self.sparsity*self.dim)),
chunk_size)
def create_dataset(self, group, chunk_size):
"""Create an empty index dataset in the given group."""
dtype=np.int64
chunks = (_nb_per_chunk(np.dtype(dtype).itemsize, 1, chunk_size),)
group.create_dataset(self.name, (0,), dtype=dtype,
chunks=chunks, maxshape=(None,))
