mindspore.dataset.Dataset.flat_map
- Dataset.flat_map(func)[source]
Map func to each row in dataset and flatten the result.
- Parameters
func (function) – A function that must take one numpy.ndarray as an argument and return a Dataset .
- Returns
Dataset, a new dataset with the above operation applied.
Examples
>>> import mindspore.dataset as ds >>> # 1) flat_map on one column dataset >>> dataset = ds.NumpySlicesDataset([[0, 1], [2, 3]], shuffle=False) >>> >>> def repeat(array): ... # create a NumpySlicesDataset with the array ... data = ds.NumpySlicesDataset(array, shuffle=False) ... # repeat the dataset twice ... data = data.repeat(2) ... return data >>> >>> dataset = dataset.flat_map(repeat) >>> # [0, 1, 0, 1, 2, 3, 2, 3] >>> >>> # 2) flat_map on multi column dataset >>> dataset = ds.NumpySlicesDataset(([[0, 1], [2, 3]], [[0, -1], [-2, -3]]), shuffle=False) >>> >>> def plus_and_minus(col1, col2): ... # apply different methods on columns ... data = ds.NumpySlicesDataset((col1 + 1, col2 - 1), shuffle=False) ... return data >>> >>> dataset = dataset.flat_map(plus_and_minus) >>> # ([1, 2, 3, 4], [-1, -2, -3, -4])