RowSparseNDArray¶

class mxnet.ndarray.sparse.RowSparseNDArray(handle, writable=True)[source]¶

A sparse representation of a set of NDArray row slices at given indices.

A RowSparseNDArray represents a multidimensional NDArray using two separate arrays: data and indices. The number of dimensions has to be at least 2.

data: an NDArray of any dtype with shape [D0, D1, …, Dn].
indices: a 1-D int64 NDArray with shape [D0] with values sorted in ascending order.

The indices stores the indices of the row slices with non-zeros, while the values are stored in data. The corresponding NDArray dense represented by RowSparseNDArray rsp has

dense[rsp.indices[i], :, :, :, ...] = rsp.data[i, :, :, :, ...]

>>> dense.asnumpy()
array([[ 1.,  2., 3.],
       [ 0.,  0., 0.],
       [ 4.,  0., 5.],
       [ 0.,  0., 0.],
       [ 0.,  0., 0.]], dtype=float32)
>>> rsp = dense.tostype('row_sparse')
>>> rsp.indices.asnumpy()
array([0, 2], dtype=int64)
>>> rsp.data.asnumpy()
array([[ 1.,  2., 3.],
       [ 4.,  0., 5.]], dtype=float32)

A RowSparseNDArray is typically used to represent non-zero row slices of a large NDArray of shape [LARGE0, D1, .. , Dn] where LARGE0 >> D0 and most row slices are zeros.

RowSparseNDArray is used principally in the definition of gradients for operations that have sparse gradients (e.g. sparse dot and sparse embedding).

Array attributes¶

`RowSparseNDArray.context`	Device context of the array.
`RowSparseNDArray.data`	A deep copy NDArray of the data array of the RowSparseNDArray.
`RowSparseNDArray.dtype`	Data-type of the array’s elements.
`RowSparseNDArray.indices`	A deep copy NDArray of the indices array of the RowSparseNDArray.
`RowSparseNDArray.shape`	Tuple of array dimensions.
`RowSparseNDArray.stype`	Storage-type of the array.

Array conversion¶

`RowSparseNDArray.as_in_context`	Returns an array on the target device with the same value as this array.
`RowSparseNDArray.asnumpy`	Return a dense `numpy.ndarray` object with value copied from this array
`RowSparseNDArray.asscalar`	Returns a scalar whose value is copied from this array.
`RowSparseNDArray.astype`	Returns a copy of the array after casting to a specified type.
`RowSparseNDArray.copy`	Makes a copy of this `NDArray`, keeping the same context.
`RowSparseNDArray.copyto`	Copies the value of this array to another array.
`RowSparseNDArray.tostype`	Return a copy of the array with chosen storage type.

Array inspection¶

RowSparseNDArray.check_format Check whether the NDArray format is valid.

Array creation¶

RowSparseNDArray.zeros_like Convenience fluent method for zeros_like().

Array reduction¶

RowSparseNDArray.norm Convenience fluent method for norm().

Array rounding¶

`RowSparseNDArray.ceil`	Convenience fluent method for `ceil()`.
`RowSparseNDArray.fix`	Convenience fluent method for `fix()`.
`RowSparseNDArray.floor`	Convenience fluent method for `floor()`.
`RowSparseNDArray.rint`	Convenience fluent method for `rint()`.
`RowSparseNDArray.round`	Convenience fluent method for `round()`.
`RowSparseNDArray.trunc`	Convenience fluent method for `trunc()`.

Trigonometric functions¶

`RowSparseNDArray.arcsin`	Convenience fluent method for `arcsin()`.
`RowSparseNDArray.arctan`	Convenience fluent method for `arctan()`.
`RowSparseNDArray.degrees`	Convenience fluent method for `degrees()`.
`RowSparseNDArray.radians`	Convenience fluent method for `radians()`.
`RowSparseNDArray.sin`	Convenience fluent method for `sin()`.
`RowSparseNDArray.tan`	Convenience fluent method for `tan()`.

Hyperbolic functions¶

`RowSparseNDArray.arcsinh`	Convenience fluent method for `arcsinh()`.
`RowSparseNDArray.arctanh`	Convenience fluent method for `arctanh()`.
`RowSparseNDArray.sinh`	Convenience fluent method for `sinh()`.
`RowSparseNDArray.tanh`	Convenience fluent method for `tanh()`.

Exponents and logarithms¶

`RowSparseNDArray.expm1`	Convenience fluent method for `expm1()`.
`RowSparseNDArray.log1p`	Convenience fluent method for `log1p()`.

Powers¶

`RowSparseNDArray.sqrt`	Convenience fluent method for `sqrt()`.
`RowSparseNDArray.square`	Convenience fluent method for `square()`.

Indexing¶

`RowSparseNDArray.__getitem__`	x.__getitem__(i) <=> x[i]
`RowSparseNDArray.__setitem__`	x.__setitem__(i, y) <=> x[i]=y
`RowSparseNDArray.retain`	Convenience fluent method for `retain()`.

Lazy evaluation¶

RowSparseNDArray.wait_to_read Waits until all previous write operations on the current array are finished.

Miscellaneous¶

`RowSparseNDArray.abs`	Convenience fluent method for `abs()`.
`RowSparseNDArray.clip`	Convenience fluent method for `clip()`.
`RowSparseNDArray.sign`	Convenience fluent method for `sign()`.