def get_dataset(ctx, shape, tileshape, num_partitions, sig_dims, use_roi=False): data = _mk_random(shape) dataset = MemoryDataSet(data=data, tileshape=tileshape, num_partitions=num_partitions, sig_dims=sig_dims) dataset.initialize(ctx) if use_roi: roi = np.random.choice([True, False], dataset._shape.nav) else: roi = None return {'data': data, 'dataset': dataset, 'roi': roi}