oneflow.Tensor

.. The documentation is referenced from: https://pytorch.org/docs/1.10/tensors.html

A :class:oneflow.Tensor is a multi-dimensional matrix containing elements of a single data type.

.. currentmodule:: oneflow

Data types

OneFlow defines 8 Tensor types with CPU and GPU variants which are as follows:

======================================= =============================================== =============================== ================================== Data type dtype CPU tensor GPU tensor ======================================= =============================================== =============================== ================================== Boolean oneflow.bool :class:oneflow.BoolTensor :class:oneflow.cuda.BoolTensor 8-bit integer (unsigned) oneflow.uint8 :class:oneflow.ByteTensor :class:oneflow.cuda.ByteTensor 8-bit integer (signed) oneflow.int8 :class:oneflow.CharTensor :class:oneflow.cuda.CharTensor 64-bit floating point oneflow.float64 or oneflow.double :class:oneflow.DoubleTensor :class:oneflow.cuda.DoubleTensor 32-bit floating point oneflow.float32 or oneflow.float :class:oneflow.FloatTensor :class:oneflow.cuda.FloatTensor 16-bit floating point oneflow.float16 or oneflow.half :class:oneflow.HalfTensor :class:oneflow.cuda.HalfTensor 32-bit integer (signed) oneflow.int32 or oneflow.int :class:oneflow.IntTensor :class:oneflow.cuda.IntTensor 64-bit integer (signed) oneflow.int64 or oneflow.long :class:oneflow.LongTensor :class:oneflow.cuda.LongTensor ======================================= =============================================== =============================== ==================================

Initializing and basic operations

A tensor can be constructed from a Python :class:list or sequence using the :func:oneflow.tensor constructor:

>>> import oneflow
>>> import numpy as np
>>> oneflow.tensor([[1., -1.], [1., -1.]])
tensor([[ 1., -1.],
        [ 1., -1.]], dtype=oneflow.float32)
>>> oneflow.tensor(np.array([[1, 2, 3], [4, 5, 6]]))
tensor([[ 1, 2, 3],
        [ 4, 5, 6]], dtype=oneflow.int64)

.. warning::

:func:`oneflow.tensor` always copies :attr:`data`. If you have a Tensor
:attr:`data` and just want to change its ``requires_grad`` flag, use
:meth:`~oneflow.Tensor.requires_grad_` or
:meth:`~oneflow.Tensor.detach` to avoid a copy.
If you have a numpy array and want to avoid a copy, use
:func:`oneflow.as_tensor`.

.. A tensor of specific data type can be constructed by passing a :class:oneflow.dtype and/or a :class:oneflow.device to a constructor or tensor creation op:

>>> import oneflow
>>> oneflow.zeros([2, 4], dtype=oneflow.int32)
tensor([[ 0, 0, 0, 0],
        [ 0, 0, 0, 0]], dtype=oneflow.int32)
>>> cuda0 = oneflow.device('cuda:0')
>>> oneflow.ones([2, 4], dtype=oneflow.float64, device=cuda0)
tensor([[ 1., 1., 1., 1.],
        [ 1., 1., 1., 1.]], device='cuda:0', dtype=oneflow.float64)

For more information about building tensors, see :ref:tensor-creation-ops

The contents of a tensor can be accessed and modified using Python's indexing and slicing notation:

>>> import oneflow
>>> x = oneflow.tensor([[1, 2, 3], [4, 5, 6]])
>>> print(x[1][2])
tensor(6, dtype=oneflow.int64)
>>> x[0][1] = 8
>>> print(x)
tensor([[1, 8, 3],
        [4, 5, 6]], dtype=oneflow.int64)

Use :meth:oneflow.Tensor.item to get a Python number from a tensor containing a single value:

>>> import oneflow
>>> x = oneflow.tensor([[1]])
>>> x
tensor([[1]], dtype=oneflow.int64)
>>> x.item()
1
>>> x = oneflow.tensor(2.5)
>>> x
tensor(2.5000, dtype=oneflow.float32)
>>> x.item()
2.5

For more information about indexing, see :ref:indexing-slicing-joining

A tensor can be created with :attr:requires_grad=True so that :mod:oneflow.autograd records operations on them for automatic differentiation.

>>> import oneflow
>>> x = oneflow.tensor([[1., -1.], [1., 1.]], requires_grad=True)
>>> out = x.pow(2).sum()
>>> out.backward()
>>> x.grad
tensor([[ 2., -2.],
        [ 2.,  2.]], dtype=oneflow.float32)

.. note:: For more information on the :class:oneflow.dtype, :class:oneflow.device, and :class:oneflow.layout attributes of a :class:oneflow.Tensor, see :ref:tensor-attributes-doc.

.. note:: Methods which mutate a tensor are marked with an underscore suffix. For example, :func:oneflow.FloatTensor.add_ computes the absolute value in-place and returns the modified tensor, while :func:oneflow.FloatTensor.add computes the result in a new tensor.

.. note:: To change an existing tensor's :class:oneflow.device and/or :class:oneflow.dtype, consider using :meth:~oneflow.Tensor.to method of Tensor object.

.. warning:: Current implementation of :class:oneflow.Tensor introduces memory overhead, thus it might lead to unexpectedly high memory usage in the applications with many tiny tensors. If this is your case, consider using one large structure.

Tensor class reference

.. class:: Tensor()

There are a few main ways to create a tensor, depending on your use case.

To create a tensor with pre-existing data, use :func:oneflow.tensor.
To create a tensor with specific size, use oneflow.* tensor creation ops (see :ref:tensor-creation-ops).
To create a tensor with the same size (and similar types) as another tensor, use oneflow.*_like tensor creation ops (see :ref:tensor-creation-ops).

.. currentmodule:: oneflow .. autosummary:: :toctree: generated :nosignatures:

Tensor.new_empty
Tensor.new_ones 
Tensor.new_zeros
Tensor.new_full
Tensor.new_tensor
Tensor.is_cuda
Tensor.is_global
Tensor.device
Tensor.grad
Tensor.ndim
Tensor.abs
Tensor.acos
Tensor.acosh
Tensor.add
Tensor.add_
Tensor.addcdiv
Tensor.addcdiv_
Tensor.addcmul
Tensor.addcmul_
Tensor.addmm
Tensor.all
Tensor.amin
Tensor.amax
Tensor.any
Tensor.arccos
Tensor.arccosh
Tensor.arcsin
Tensor.arcsinh
Tensor.arctan
Tensor.arctanh
Tensor.argmax
Tensor.argmin
Tensor.argsort
Tensor.argwhere
Tensor.asin
Tensor.asinh
Tensor.atan
Tensor.atan2
Tensor.atanh
Tensor.backward
Tensor.bmm
Tensor.bool
Tensor.byte
Tensor.cast
Tensor.ceil
Tensor.ceil_
Tensor.chunk
Tensor.clamp
Tensor.clamp_
Tensor.clip
Tensor.clip_
Tensor.clone
Tensor.contiguous
Tensor.copy_
Tensor.cos
Tensor.cosh
Tensor.cpu
Tensor.cuda
Tensor.cumprod
Tensor.cumsum
Tensor.data
Tensor.dot
Tensor.detach
Tensor.placement
Tensor.sbp
Tensor.diag
Tensor.diagonal
Tensor.dim
Tensor.div
Tensor.div_
Tensor.double
Tensor.dtype 
Tensor.digamma
Tensor.element_size
Tensor.eq
Tensor.equal
Tensor.erf
Tensor.erfc
Tensor.erfinv
Tensor.erfinv_
Tensor.exp
Tensor.exp2
Tensor.expand
Tensor.expand_as
Tensor.expm1
Tensor.fill_
Tensor.flatten
Tensor.flip
Tensor.float
Tensor.floor
Tensor.floor_
Tensor.floor_divide
Tensor.fmod
Tensor.gather
Tensor.ge
Tensor.get_device
Tensor.grad_fn
Tensor.gt
Tensor.gt_
Tensor.half
Tensor.in_top_k
Tensor.index_select
Tensor.index_add
Tensor.index_add_
Tensor.int
Tensor.is_contiguous
Tensor.is_floating_point
Tensor.is_lazy
Tensor.is_leaf
Tensor.isinf
Tensor.isnan
Tensor.item
Tensor.le
Tensor.lerp
Tensor.lerp_
Tensor.log
Tensor.log1p
Tensor.log2
Tensor.log10
Tensor.logical_and
Tensor.logical_or
Tensor.logical_not
Tensor.logical_xor
Tensor.long
Tensor.lt
Tensor.masked_fill
Tensor.masked_fill_
Tensor.masked_select
Tensor.matmul
Tensor.mm
Tensor.mv
Tensor.max
Tensor.maximum
Tensor.median
Tensor.mean
Tensor.min
Tensor.minimum
Tensor.mish
Tensor.mode
Tensor.mul
Tensor.mul_
Tensor.frac
Tensor.frac_
Tensor.nansum
Tensor.narrow
Tensor.ndimension
Tensor.ne
Tensor.neg
Tensor.negative
Tensor.nelement
Tensor.nonzero
Tensor.norm
Tensor.normal_
Tensor.numel
Tensor.numpy
Tensor.offload
Tensor.load
Tensor.is_offloaded
Tensor.permute
Tensor.pow
Tensor.prod
Tensor.quantile
Tensor.reciprocal
Tensor.register_hook
Tensor.relu
Tensor.repeat
Tensor.repeat_interleave
Tensor.requires_grad
Tensor.requires_grad_
Tensor.reshape
Tensor.reshape_as
Tensor.retain_grad
Tensor.roll
Tensor.round
Tensor.round_
Tensor.rsqrt
Tensor.selu
Tensor.shape
Tensor.sigmoid
Tensor.sign
Tensor.silu
Tensor.sin
Tensor.sin_
Tensor.sinh
Tensor.size
Tensor.softmax
Tensor.softplus
Tensor.softsign
Tensor.sort
Tensor.split
Tensor.sqrt
Tensor.square
Tensor.squeeze
Tensor.squeeze_
Tensor.std
Tensor.storage_offset
Tensor.stride
Tensor.logsumexp
Tensor.sum
Tensor.swapaxes
Tensor.swapdims
Tensor.sub
Tensor.sub_
Tensor.tan
Tensor.tanh
Tensor.tile
Tensor.to
Tensor.local_to_global
Tensor.global_to_global
Tensor.to_global
Tensor.to_local
Tensor.to_consistent
Tensor.tolist
Tensor.topk
Tensor.transpose
Tensor.tril
Tensor.triu
Tensor.trunc
Tensor.type_as
Tensor.type
Tensor.t
Tensor.T
Tensor.unbind
Tensor.unfold
Tensor.uniform_
Tensor.unsqueeze
Tensor.unsqueeze_
Tensor.as_strided
Tensor.as_strided_
Tensor.var
Tensor.view
Tensor.view_as
Tensor.where
Tensor.zero_
Tensor.nms
Tensor.pin_memory
Tensor.is_pinned
Tensor.inverse
Tensor.cross
Tensor.scatter
Tensor.scatter_
Tensor.scatter_add
Tensor.scatter_add_
Tensor.bernoulli
Tensor.bernoulli_
Tensor.bincount
Tensor.isclose
Tensor.allclose
Tensor.broadcast_to
Tensor.unique
Tensor.bitwise_and
Tensor.bitwise_or
Tensor.bitwise_xor
Tensor.baddbmm