torch(七)、Math operations(1)

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发布于 2019-09-25 16:15:12

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本文链接：https://blog.csdn.net/weixin_36670529/article/details/101199430

`torch.abs`(input, out=None) → Tensor

Computes the element-wise absolute value of the given input tensor.

outi=∣inputi∣\text{out}_{i} = |\text{input}_{i}| outi=∣inputi∣

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> torch.abs(torch.tensor([-1, -2, 3]))
tensor([ 1,  2,  3])

`torch.acos`(input, out=None) → Tensor

Returns a new tensor with the arccosine of the elements of input.

outi=cos⁡−1(inputi)\text{out}_{i} = \cos^{-1}(\text{input}_{i}) outi=cos−1(inputi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.3348, -0.5889,  0.2005, -0.1584])
>>> torch.acos(a)
tensor([ 1.2294,  2.2004,  1.3690,  1.7298])

`torch.add`()

torch.add(input, other, out=None)

Adds the scalar other to each element of the input input and returns a new resulting tensor.

out=input+other\text{out} = \text{input} + \text{other} out=input+other

If input is of type FloatTensor or DoubleTensor, other must be a real number, otherwise it should be an integer.

Parameters

input (Tensor) – the input tensor.
value (Number) – the number to be added to each element of input

Keyword Arguments

out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.0202,  1.0985,  1.3506, -0.6056])
>>> torch.add(a, 20)
tensor([ 20.0202,  21.0985,  21.3506,  19.3944])

`torch.add`(input, alpha=1, other, out=None)

Each element of the tensor other is multiplied by the scalar alpha and added to each element of the tensor input. The resulting tensor is returned.

The shapes of input and other must be broadcastable.

out=input+alpha×other\text{out} = \text{input} + \text{alpha} \times \text{other} out=input+alpha×other

If other is of type FloatTensor or DoubleTensor, alpha must be a real number, otherwise it should be an integer.

Parameters

input (Tensor) – the first input tensor
alpha (Number) – the scalar multiplier for other
other (Tensor) – the second input tensor

Keyword Arguments

out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([-0.9732, -0.3497,  0.6245,  0.4022])
>>> b = torch.randn(4, 1)
>>> b
tensor([[ 0.3743],
        [-1.7724],
        [-0.5811],
        [-0.8017]])
>>> torch.add(a, 10, b)
tensor([[  2.7695,   3.3930,   4.3672,   4.1450],
        [-18.6971, -18.0736, -17.0994, -17.3216],
        [ -6.7845,  -6.1610,  -5.1868,  -5.4090],
        [ -8.9902,  -8.3667,  -7.3925,  -7.6147]])

`torch.addcdiv`(input, value=1, tensor1, tensor2, out=None) → Tensor

Performs the element-wise division of tensor1 by tensor2, multiply the result by the scalar value and add it to input.

outi=inputi+value×tensor1itensor2i\text{out}_i = \text{input}_i + \text{value} \times \frac{\text{tensor1}_i}{\text{tensor2}_i} outi=inputi+value×tensor2itensor1i

The shapes of input, tensor1, and tensor2 must be broadcastable.

For inputs of type FloatTensor or DoubleTensor, value must be a real number, otherwise an integer.

Parameters

input (Tensor) – the tensor to be added
value (Number, optional) – multiplier for tensor1/tensor2\text{tensor1} / \text{tensor2}tensor1/tensor2
tensor1 (Tensor) – the numerator tensor
tensor2 (Tensor) – the denominator tensor
out (Tensor, optional) – the output tensor.

Example:

>>> t = torch.randn(1, 3)
>>> t1 = torch.randn(3, 1)
>>> t2 = torch.randn(1, 3)
>>> torch.addcdiv(t, 0.1, t1, t2)
tensor([[-0.2312, -3.6496,  0.1312],
        [-1.0428,  3.4292, -0.1030],
        [-0.5369, -0.9829,  0.0430]])

`torch.addcmul`(input, value=1, tensor1, tensor2, out=None) → Tensor

Performs the element-wise multiplication of tensor1 by tensor2, multiply the result by the scalar value and add it to input.

outi=inputi+value×tensor1i×tensor2i\text{out}_i = \text{input}_i + \text{value} \times \text{tensor1}_i \times \text{tensor2}_i outi=inputi+value×tensor1i×tensor2i

The shapes of tensor, tensor1, and tensor2 must be broadcastable.

For inputs of type FloatTensor or DoubleTensor, value must be a real number, otherwise an integer.

Parameters

input (Tensor) – the tensor to be added
value (Number, optional) – multiplier for tensor1.∗tensor2tensor1 .* tensor2tensor1.∗tensor2
tensor1 (Tensor) – the tensor to be multiplied
tensor2 (Tensor) – the tensor to be multiplied
out (Tensor, optional) – the output tensor.

Example:

>>> t = torch.randn(1, 3)
>>> t1 = torch.randn(3, 1)
>>> t2 = torch.randn(1, 3)
>>> torch.addcmul(t, 0.1, t1, t2)
tensor([[-0.8635, -0.6391,  1.6174],
        [-0.7617, -0.5879,  1.7388],
        [-0.8353, -0.6249,  1.6511]])

`torch.asin`(input, out=None) → Tensor

Returns a new tensor with the arcsine of the elements of input.

outi=sin⁡−1(inputi)\text{out}_{i} = \sin^{-1}(\text{input}_{i}) outi=sin−1(inputi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([-0.5962,  1.4985, -0.4396,  1.4525])
>>> torch.asin(a)
tensor([-0.6387,     nan, -0.4552,     nan])

`torch.atan`(input, out=None) → Tensor

Returns a new tensor with the arctangent of the elements of input.

outi=tan⁡−1(inputi)\text{out}_{i} = \tan^{-1}(\text{input}_{i}) outi=tan−1(inputi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.2341,  0.2539, -0.6256, -0.6448])
>>> torch.atan(a)
tensor([ 0.2299,  0.2487, -0.5591, -0.5727])

`torch.atan2`(input, other, out=None) → Tensor

Element-wise arctangent of inputi/otheri\text{input}_{i} / \text{other}_{i}inputi/otheri with consideration of the quadrant. Returns a new tensor with the signed angles in radians between vector (otheri,inputi)(\text{other}_{i}, \text{input}_{i})(otheri,inputi) and vector (1,0)(1, 0)(1,0) . (Note that otheri\text{other}_{i}otheri , the second parameter, is the x-coordinate, while inputi\text{input}_{i}inputi , the first parameter, is the y-coordinate.)

The shapes of input and other must be broadcastable.

Parameters

input (Tensor) – the first input tensor
other (Tensor) – the second input tensor
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.9041,  0.0196, -0.3108, -2.4423])
>>> torch.atan2(a, torch.randn(4))
tensor([ 0.9833,  0.0811, -1.9743, -1.4151])

`torch.bitwise_not`(input, out=None) → Tensor

Computes the bitwise NOT of the given input tensor. The input tensor must be of integral or Boolean types. For bool tensors, it computes the logical NOT.

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example

>>> torch.bitwise_not(torch.tensor([-1, -2, 3], dtype=torch.int8))
tensor([ 0,  1, -4], dtype=torch.int8)

`torch.ceil`(input, out=None) → Tensor

Returns a new tensor with the ceil of the elements of input, the smallest integer greater than or equal to each element.

outi=⌈inputi⌉=⌊inputi⌋+1\text{out}_{i} = \left\lceil \text{input}_{i} \right\rceil = \left\lfloor \text{input}_{i} \right\rfloor + 1 outi=⌈inputi⌉=⌊inputi⌋+1

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([-0.6341, -1.4208, -1.0900,  0.5826])
>>> torch.ceil(a)
tensor([-0., -1., -1.,  1.])

`torch.clamp`(input, min, max, out=None) → Tensor

Clamp all elements in input into the range [ min, max ] and return a resulting tensor:

yi={minif xi<minxiif min≤xi≤maxmaxif xi>maxy_i = \begin{cases} \text{min} & \text{if } x_i < \text{min} \\ x_i & \text{if } \text{min} \leq x_i \leq \text{max} \\ \text{max} & \text{if } x_i > \text{max} \end{cases} yi=⎩⎪⎪⎨⎪⎪⎧minximaxif xi<minif min≤xi≤maxif xi>max

If input is of type FloatTensor or DoubleTensor, args min and max must be real numbers, otherwise they should be integers.

Parameters

input (Tensor) – the input tensor.
min (Number) – lower-bound of the range to be clamped to
max (Number) – upper-bound of the range to be clamped to
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([-1.7120,  0.1734, -0.0478, -0.0922])
>>> torch.clamp(a, min=-0.5, max=0.5)
tensor([-0.5000,  0.1734, -0.0478, -0.0922])

`torch.clamp`(input, , min, out=None*) → Tensor

Clamps all elements in input to be larger or equal min.

If input is of type FloatTensor or DoubleTensor, value should be a real number, otherwise it should be an integer.

Parameters

input (Tensor) – the input tensor.
value (Number) – minimal value of each element in the output
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([-0.0299, -2.3184,  2.1593, -0.8883])
>>> torch.clamp(a, min=0.5)
tensor([ 0.5000,  0.5000,  2.1593,  0.5000])

`torch.clamp`(input, , max, out=None*) → Tensor

Clamps all elements in input to be smaller or equal max.

If input is of type FloatTensor or DoubleTensor, value should be a real number, otherwise it should be an integer.

Parameters

input (Tensor) – the input tensor.
value (Number) – maximal value of each element in the output
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.7753, -0.4702, -0.4599,  1.1899])
>>> torch.clamp(a, max=0.5)
tensor([ 0.5000, -0.4702, -0.4599,  0.5000])

`torch.cos`(input, out=None) → Tensor

Returns a new tensor with the cosine of the elements of input.

outi=cos⁡(inputi)\text{out}_{i} = \cos(\text{input}_{i}) outi=cos(inputi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 1.4309,  1.2706, -0.8562,  0.9796])
>>> torch.cos(a)
tensor([ 0.1395,  0.2957,  0.6553,  0.5574])

`torch.cosh`(input, out=None) → Tensor

Returns a new tensor with the hyperbolic cosine of the elements of input.

outi=cosh⁡(inputi)\text{out}_{i} = \cosh(\text{input}_{i}) outi=cosh(inputi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.1632,  1.1835, -0.6979, -0.7325])
>>> torch.cosh(a)
tensor([ 1.0133,  1.7860,  1.2536,  1.2805])

`torch.div`()

torch.div(input, other, out=None) → Tensor

Divides each element of the input input with the scalar other and returns a new resulting tensor.

outi=inputiother\text{out}_i = \frac{\text{input}_i}{\text{other}} outi=otherinputi

If input is of type FloatTensor or DoubleTensor, other should be a real number, otherwise it should be an integer

Parameters

{input} –
other (Number) – the number to be divided to each element of input
{out} –

Example:

>>> a = torch.randn(5)
>>> a
tensor([ 0.3810,  1.2774, -0.2972, -0.3719,  0.4637])
>>> torch.div(a, 0.5)
tensor([ 0.7620,  2.5548, -0.5944, -0.7439,  0.9275])

`torch.div`(input, other, out=None) → Tensor

Each element of the tensor input is divided by each element of the tensor other. The resulting tensor is returned. The shapes of input and other must be broadcastable.

outi=inputiotheri\text{out}_i = \frac{\text{input}_i}{\text{other}_i} outi=otheriinputi

Parameters

input (Tensor) – the numerator tensor
other (Tensor) – the denominator tensor
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[-0.3711, -1.9353, -0.4605, -0.2917],
        [ 0.1815, -1.0111,  0.9805, -1.5923],
        [ 0.1062,  1.4581,  0.7759, -1.2344],
        [-0.1830, -0.0313,  1.1908, -1.4757]])
>>> b = torch.randn(4)
>>> b
tensor([ 0.8032,  0.2930, -0.8113, -0.2308])
>>> torch.div(a, b)
tensor([[-0.4620, -6.6051,  0.5676,  1.2637],
        [ 0.2260, -3.4507, -1.2086,  6.8988],
        [ 0.1322,  4.9764, -0.9564,  5.3480],
        [-0.2278, -0.1068, -1.4678,  6.3936]])

`torch.digamma`(input, out=None) → Tensor

Computes the logarithmic derivative of the gamma function on input.

ψ(x)=ddxln⁡(Γ(x))=Γ′(x)Γ(x)\psi(x) = \frac{d}{dx} \ln\left(\Gamma\left(x\right)\right) = \frac{\Gamma'(x)}{\Gamma(x)} ψ(x)=dxdln(Γ(x))=Γ(x)Γ′(x)

Parameters

input (Tensor) – the tensor to compute the digamma function on

Example:

>>> a = torch.tensor([1, 0.5])
>>> torch.digamma(a)
tensor([-0.5772, -1.9635])

`torch.erf`(input, out=None) → Tensor

Computes the error function of each element. The error function is defined as follows:

erf(x)=2π∫0xe−t2dt\mathrm{erf}(x) = \frac{2}{\sqrt{\pi}} \int_{0}^{x} e^{-t^2} dt erf(x)=π

2∫0xe−t2dt

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> torch.erf(torch.tensor([0, -1., 10.]))
tensor([ 0.0000, -0.8427,  1.0000])

`torch.erfc`(input, out=None) → Tensor

Computes the complementary error function of each element of input. The complementary error function is defined as follows:

erfc(x)=1−2π∫0xe−t2dt\mathrm{erfc}(x) = 1 - \frac{2}{\sqrt{\pi}} \int_{0}^{x} e^{-t^2} dt erfc(x)=1−π

2∫0xe−t2dt

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> torch.erfc(torch.tensor([0, -1., 10.]))
tensor([ 1.0000, 1.8427,  0.0000])

`torch.erfinv`(input, out=None) → Tensor

Computes the inverse error function of each element of input. The inverse error function is defined in the range (−1,1)(-1, 1)(−1,1) as:

erfinv(erf(x))=x\mathrm{erfinv}(\mathrm{erf}(x)) = x erfinv(erf(x))=x

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> torch.erfinv(torch.tensor([0, 0.5, -1.]))
tensor([ 0.0000,  0.4769,    -inf])

`torch.exp`(input, out=None) → Tensor

Returns a new tensor with the exponential of the elements of the input tensor input.

yi=exiy_{i} = e^{x_{i}} yi=exi

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> torch.exp(torch.tensor([0, math.log(2.)]))
tensor([ 1.,  2.])

`torch.expm1`(input, out=None) → Tensor

Returns a new tensor with the exponential of the elements minus 1 of input.

yi=exi−1y_{i} = e^{x_{i}} - 1 yi=exi−1

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> torch.expm1(torch.tensor([0, math.log(2.)]))
tensor([ 0.,  1.])

`torch.floor`(input, out=None) → Tensor

Returns a new tensor with the floor of the elements of input, the largest integer less than or equal to each element.

outi=⌊inputi⌋\text{out}_{i} = \left\lfloor \text{input}_{i} \right\rfloor outi=⌊inputi⌋

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([-0.8166,  1.5308, -0.2530, -0.2091])
>>> torch.floor(a)
tensor([-1.,  1., -1., -1.])

`torch.fmod`(input, other, out=None) → Tensor

Computes the element-wise remainder of division.

The dividend and divisor may contain both for integer and floating point numbers. The remainder has the same sign as the dividend input.

When other is a tensor, the shapes of input and other must be broadcastable.

Parameters

input (Tensor) – the dividend
other (Tensor or float) – the divisor, which may be either a number or a tensor of the same shape as the dividend
out (Tensor, optional) – the output tensor.

Example:

>>> torch.fmod(torch.tensor([-3., -2, -1, 1, 2, 3]), 2)
tensor([-1., -0., -1.,  1.,  0.,  1.])
>>> torch.fmod(torch.tensor([1., 2, 3, 4, 5]), 1.5)
tensor([ 1.0000,  0.5000,  0.0000,  1.0000,  0.5000])

`torch.frac`(input, out=None) → Tensor

Computes the fractional portion of each element in input.

outi=inputi−⌊∣inputi∣⌋∗sgn⁡(inputi)\text{out}_{i} = \text{input}_{i} - \left\lfloor |\text{input}_{i}| \right\rfloor * \operatorname{sgn}(\text{input}_{i}) outi=inputi−⌊∣inputi∣⌋∗sgn(inputi)

Example:

>>> torch.frac(torch.tensor([1, 2.5, -3.2]))
tensor([ 0.0000,  0.5000, -0.2000])

`torch.lerp`(input, end, weight, out=None)

Does a linear interpolation of two tensors start (given by input) and end based on a scalar or tensor weight and returns the resulting out tensor.

outi=starti+weighti×(endi−starti)\text{out}_i = \text{start}_i + \text{weight}_i \times (\text{end}_i - \text{start}_i) outi=starti+weighti×(endi−starti)

The shapes of start and end must be broadcastable. If weight is a tensor, then the shapes of weight, start, and end must be broadcastable.

Parameters

input (Tensor) – the tensor with the starting points
end (Tensor) – the tensor with the ending points
weight (float or tensor) – the weight for the interpolation formula
out (Tensor, optional) – the output tensor.

Example:

>>> start = torch.arange(1., 5.)
>>> end = torch.empty(4).fill_(10)
>>> start
tensor([ 1.,  2.,  3.,  4.])
>>> end
tensor([ 10.,  10.,  10.,  10.])
>>> torch.lerp(start, end, 0.5)
tensor([ 5.5000,  6.0000,  6.5000,  7.0000])
>>> torch.lerp(start, end, torch.full_like(start, 0.5))
tensor([ 5.5000,  6.0000,  6.5000,  7.0000])

`torch.log`(input, out=None) → Tensor

Returns a new tensor with the natural logarithm of the elements of input.

yi=log⁡e(xi)y_{i} = \log_{e} (x_{i}) yi=loge(xi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(5)
>>> a
tensor([-0.7168, -0.5471, -0.8933, -1.4428, -0.1190])
>>> torch.log(a)
tensor([ nan,  nan,  nan,  nan,  nan])

`torch.log10`(input, out=None) → Tensor

Returns a new tensor with the logarithm to the base 10 of the elements of input.

yi=log⁡10(xi)y_{i} = \log_{10} (x_{i}) yi=log10(xi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.rand(5)
>>> a
tensor([ 0.5224,  0.9354,  0.7257,  0.1301,  0.2251])


>>> torch.log10(a)
tensor([-0.2820, -0.0290, -0.1392, -0.8857, -0.6476])

`torch.log1p`(input, out=None) → Tensor

Returns a new tensor with the natural logarithm of (1 + input).

yi=log⁡e(xi+1)y_i = \log_{e} (x_i + 1) yi=loge(xi+1)

Note

This function is more accurate than torch.log() for small values of input

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(5)
>>> a
tensor([-1.0090, -0.9923,  1.0249, -0.5372,  0.2492])
>>> torch.log1p(a)
tensor([    nan, -4.8653,  0.7055, -0.7705,  0.2225])

`torch.log2`(input, out=None) → Tensor

Returns a new tensor with the logarithm to the base 2 of the elements of input.

yi=log⁡2(xi)y_{i} = \log_{2} (x_{i}) yi=log2(xi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.rand(5)
>>> a
tensor([ 0.8419,  0.8003,  0.9971,  0.5287,  0.0490])


>>> torch.log2(a)
tensor([-0.2483, -0.3213, -0.0042, -0.9196, -4.3504])

`torch.logical_not`(input, out=None) → Tensor

Computes the element-wise logical NOT of the given input tensor. If not specified, the output tensor will have the bool dtype. If the input tensor is not a bool tensor, zeros are treated as False and non-zeros are treated as True.

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> torch.logical_not(torch.tensor([True, False]))
tensor([ False,  True])
>>> torch.logical_not(torch.tensor([0, 1, -10], dtype=torch.int8))
tensor([ True, False, False])
>>> torch.logical_not(torch.tensor([0., 1.5, -10.], dtype=torch.double))
tensor([ True, False, False])
>>> torch.logical_not(torch.tensor([0., 1., -10.], dtype=torch.double), out=torch.empty(3, dtype=torch.int16))
tensor([1, 0, 0], dtype=torch.int16)

`torch.logical_xor`(input, other, out=None) → Tensor

Computes the element-wise logical XOR of the given input tensors. Both input tensors must have the bool dtype.

Parameters

input (Tensor) – the input tensor.
other (Tensor) – the tensor to compute XOR with
out (Tensor, optional) – the output tensor.

Example:

>>> torch.logical_xor(torch.tensor([True, False, True]), torch.tensor([True, False, False]))
tensor([ False, False,  True])

`torch.mul`()

torch.mul(input, other, out=None)

Multiplies each element of the input input with the scalar other and returns a new resulting tensor.

outi=other×inputi\text{out}_i = \text{other} \times \text{input}_i outi=other×inputi

If input is of type FloatTensor or DoubleTensor, other should be a real number, otherwise it should be an integer

Parameters

{input} –
value (Number) – the number to be multiplied to each element of input
{out} –

Example:

>>> a = torch.randn(3)
>>> a
tensor([ 0.2015, -0.4255,  2.6087])
>>> torch.mul(a, 100)
tensor([  20.1494,  -42.5491,  260.8663])

`torch.mul`(input, other, out=None)

Each element of the tensor input is multiplied by the corresponding element of the Tensor other. The resulting tensor is returned.

The shapes of input and other must be broadcastable.

outi=inputi×otheri\text{out}_i = \text{input}_i \times \text{other}_i outi=inputi×otheri

Parameters

input (Tensor) – the first multiplicand tensor
other (Tensor) – the second multiplicand tensor
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4, 1)
>>> a
tensor([[ 1.1207],
        [-0.3137],
        [ 0.0700],
        [ 0.8378]])
>>> b = torch.randn(1, 4)
>>> b
tensor([[ 0.5146,  0.1216, -0.5244,  2.2382]])
>>> torch.mul(a, b)
tensor([[ 0.5767,  0.1363, -0.5877,  2.5083],
        [-0.1614, -0.0382,  0.1645, -0.7021],
        [ 0.0360,  0.0085, -0.0367,  0.1567],
        [ 0.4312,  0.1019, -0.4394,  1.8753]])

`torch.mvlgamma`(input, p) → Tensor

Computes the multivariate log-gamma function ([reference]) with dimension ppp element-wise, given by

log⁡(Γp(a))=C+∑i=1plog⁡(Γ(a−i−12))\log(\Gamma_{p}(a)) = C + \displaystyle \sum_{i=1}^{p} \log\left(\Gamma\left(a - \frac{i - 1}{2}\right)\right) log(Γp(a))=C+i=1∑plog(Γ(a−2i−1))

where C=log⁡(π)×p(p−1)4C = \log(\pi) \times \frac{p (p - 1)}{4}C=log(π)×4p(p−1) and Γ(⋅)\Gamma(\cdot)Γ(⋅) is the Gamma function.

If any of the elements are less than or equal to p−12\frac{p - 1}{2}2p−1 , then an error is thrown.

Parameters

input (Tensor) – the tensor to compute the multivariate log-gamma function
p (int) – the number of dimensions

Example:

>>> a = torch.empty(2, 3).uniform_(1, 2)
>>> a
tensor([[1.6835, 1.8474, 1.1929],
        [1.0475, 1.7162, 1.4180]])
>>> torch.mvlgamma(a, 2)
tensor([[0.3928, 0.4007, 0.7586],
        [1.0311, 0.3901, 0.5049]])

`torch.neg`(input, out=None) → Tensor

Returns a new tensor with the negative of the elements of input.

out=−1×input\text{out} = -1 \times \text{input} out=−1×input

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(5)
>>> a
tensor([ 0.0090, -0.2262, -0.0682, -0.2866,  0.3940])
>>> torch.neg(a)
tensor([-0.0090,  0.2262,  0.0682,  0.2866, -0.3940])

`torch.pow`()

torch.pow(input, exponent, out=None) → Tensor

Takes the power of each element in input with exponent and returns a tensor with the result.

exponent can be either a single float number or a Tensor with the same number of elements as input.

When exponent is a scalar value, the operation applied is:

outi=xiexponent\text{out}_i = x_i ^ \text{exponent} outi=xiexponent

When exponent is a tensor, the operation applied is:

outi=xiexponenti\text{out}_i = x_i ^ {\text{exponent}_i} outi=xiexponenti

When exponent is a tensor, the shapes of input and exponent must be broadcastable.

Parameters

input (Tensor) – the input tensor.
exponent (float or tensor) – the exponent value
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.4331,  1.2475,  0.6834, -0.2791])
>>> torch.pow(a, 2)
tensor([ 0.1875,  1.5561,  0.4670,  0.0779])
>>> exp = torch.arange(1., 5.)

>>> a = torch.arange(1., 5.)
>>> a
tensor([ 1.,  2.,  3.,  4.])
>>> exp
tensor([ 1.,  2.,  3.,  4.])
>>> torch.pow(a, exp)
tensor([   1.,    4.,   27.,  256.])

`torch.pow`(self, exponent, out=None) → Tensor

self is a scalar float value, and exponent is a tensor. The returned tensor out is of the same shape as exponent

The operation applied is:

outi=selfexponenti\text{out}_i = \text{self} ^ {\text{exponent}_i} outi=selfexponenti

Parameters

self (float) – the scalar base value for the power operation
exponent (Tensor) – the exponent tensor
out (Tensor, optional) – the output tensor.

Example:

>>> exp = torch.arange(1., 5.)
>>> base = 2
>>> torch.pow(base, exp)
tensor([  2.,   4.,   8.,  16.])

`torch.reciprocal`(input, out=None) → Tensor

Returns a new tensor with the reciprocal of the elements of input

outi=1inputi\text{out}_{i} = \frac{1}{\text{input}_{i}} outi=inputi1

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([-0.4595, -2.1219, -1.4314,  0.7298])
>>> torch.reciprocal(a)
tensor([-2.1763, -0.4713, -0.6986,  1.3702])

`torch.remainder`(input, other, out=None) → Tensor

Computes the element-wise remainder of division.

The divisor and dividend may contain both for integer and floating point numbers. The remainder has the same sign as the divisor.

When other is a tensor, the shapes of input and other must be broadcastable.

Parameters

input (Tensor) – the dividend
other (Tensor or float) – the divisor that may be either a number or a Tensor of the same shape as the dividend
out (Tensor, optional) – the output tensor.

Example:

>>> torch.remainder(torch.tensor([-3., -2, -1, 1, 2, 3]), 2)
tensor([ 1.,  0.,  1.,  1.,  0.,  1.])
>>> torch.remainder(torch.tensor([1., 2, 3, 4, 5]), 1.5)
tensor([ 1.0000,  0.5000,  0.0000,  1.0000,  0.5000])

`torch.round`(input, out=None) → Tensor

Returns a new tensor with each of the elements of input rounded to the closest integer.

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.9920,  0.6077,  0.9734, -1.0362])
>>> torch.round(a)
tensor([ 1.,  1.,  1., -1.])

`torch.rsqrt`(input, out=None) → Tensor

Returns a new tensor with the reciprocal of the square-root of each of the elements of input.

outi=1inputi\text{out}_{i} = \frac{1}{\sqrt{\text{input}_{i}}} outi=inputi

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([-0.0370,  0.2970,  1.5420, -0.9105])
>>> torch.rsqrt(a)
tensor([    nan,  1.8351,  0.8053,     nan])

`torch.sigmoid`(input, out=None) → Tensor

Returns a new tensor with the sigmoid of the elements of input.

outi=11+e−inputi\text{out}_{i} = \frac{1}{1 + e^{-\text{input}_{i}}} outi=1+e−inputi1

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.9213,  1.0887, -0.8858, -1.7683])
>>> torch.sigmoid(a)
tensor([ 0.7153,  0.7481,  0.2920,  0.1458])

`torch.sign`(input, out=None) → Tensor

Returns a new tensor with the signs of the elements of input.

outi=sgn⁡(inputi)\text{out}_{i} = \operatorname{sgn}(\text{input}_{i}) outi=sgn(inputi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.tensor([0.7, -1.2, 0., 2.3])
>>> a
tensor([ 0.7000, -1.2000,  0.0000,  2.3000])
>>> torch.sign(a)
tensor([ 1., -1.,  0.,  1.])

`torch.sin`(input, out=None) → Tensor

Returns a new tensor with the sine of the elements of input.

outi=sin⁡(inputi)\text{out}_{i} = \sin(\text{input}_{i}) outi=sin(inputi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([-0.5461,  0.1347, -2.7266, -0.2746])
>>> torch.sin(a)
tensor([-0.5194,  0.1343, -0.4032, -0.2711])

`torch.sinh`(input, out=None) → Tensor

Returns a new tensor with the hyperbolic sine of the elements of input.

outi=sinh⁡(inputi)\text{out}_{i} = \sinh(\text{input}_{i}) outi=sinh(inputi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.5380, -0.8632, -0.1265,  0.9399])
>>> torch.sinh(a)
tensor([ 0.5644, -0.9744, -0.1268,  1.0845])

`torch.sqrt`(input, out=None) → Tensor

Returns a new tensor with the square-root of the elements of input.

outi=inputi\text{out}_{i} = \sqrt{\text{input}_{i}} outi=inputi

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([-2.0755,  1.0226,  0.0831,  0.4806])
>>> torch.sqrt(a)
tensor([    nan,  1.0112,  0.2883,  0.6933])

`torch.tan`(input, out=None) → Tensor

Returns a new tensor with the tangent of the elements of input.

outi=tan⁡(inputi)\text{out}_{i} = \tan(\text{input}_{i}) outi=tan(inputi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([-1.2027, -1.7687,  0.4412, -1.3856])
>>> torch.tan(a)
tensor([-2.5930,  4.9859,  0.4722, -5.3366])

`torch.tanh`(input, out=None) → Tensor

Returns a new tensor with the hyperbolic tangent of the elements of input.

outi=tanh⁡(inputi)\text{out}_{i} = \tanh(\text{input}_{i}) outi=tanh(inputi)

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.8986, -0.7279,  1.1745,  0.2611])
>>> torch.tanh(a)
tensor([ 0.7156, -0.6218,  0.8257,  0.2553])

`torch.trunc`(input, out=None) → Tensor

Returns a new tensor with the truncated integer values of the elements of input.

Parameters

input (Tensor) – the input tensor.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 3.4742,  0.5466, -0.8008, -0.9079])
>>> torch.trunc(a)
tensor([ 3.,  0., -0., -0.])

Reduction Ops

`torch.argmax`()

torch.argmax(input) → LongTensor

Returns the indices of the maximum value of all elements in the input tensor.

This is the second value returned by torch.max(). See its documentation for the exact semantics of this method.

Parameters

input (Tensor) – the input tensor.

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[ 1.3398,  0.2663, -0.2686,  0.2450],
        [-0.7401, -0.8805, -0.3402, -1.1936],
        [ 0.4907, -1.3948, -1.0691, -0.3132],
        [-1.6092,  0.5419, -0.2993,  0.3195]])
>>> torch.argmax(a)
tensor(0)

`torch.argmax`(input, dim, keepdim=False) → LongTensor

Returns the indices of the maximum values of a tensor across a dimension.

This is the second value returned by torch.max(). See its documentation for the exact semantics of this method.

Parameters

input (Tensor) – the input tensor.
dim (int) – the dimension to reduce. If None, the argmax of the flattened input is returned.
keepdim (bool) – whether the output tensor has dim retained or not. Ignored if dim=None.

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[ 1.3398,  0.2663, -0.2686,  0.2450],
        [-0.7401, -0.8805, -0.3402, -1.1936],
        [ 0.4907, -1.3948, -1.0691, -0.3132],
        [-1.6092,  0.5419, -0.2993,  0.3195]])
>>> torch.argmax(a, dim=1)
tensor([ 0,  2,  0,  1])

`torch.argmin`()

torch.argmin(input) → LongTensor

Returns the indices of the minimum value of all elements in the input tensor.

This is the second value returned by torch.min(). See its documentation for the exact semantics of this method.

Parameters

input (Tensor) – the input tensor.

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[ 0.1139,  0.2254, -0.1381,  0.3687],
        [ 1.0100, -1.1975, -0.0102, -0.4732],
        [-0.9240,  0.1207, -0.7506, -1.0213],
        [ 1.7809, -1.2960,  0.9384,  0.1438]])
>>> torch.argmin(a)
tensor(13)

`torch.argmin`(input, dim, keepdim=False, out=None) → LongTensor

Returns the indices of the minimum values of a tensor across a dimension.

This is the second value returned by torch.min(). See its documentation for the exact semantics of this method.

Parameters

input (Tensor) – the input tensor.
dim (int) – the dimension to reduce. If None, the argmin of the flattened input is returned.
keepdim (bool) – whether the output tensor has dim retained or not. Ignored if dim=None.

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[ 0.1139,  0.2254, -0.1381,  0.3687],
        [ 1.0100, -1.1975, -0.0102, -0.4732],
        [-0.9240,  0.1207, -0.7506, -1.0213],
        [ 1.7809, -1.2960,  0.9384,  0.1438]])
>>> torch.argmin(a, dim=1)
tensor([ 2,  1,  3,  1])

`torch.cumprod`(input, dim, out=None, dtype=None) → Tensor

Returns the cumulative product of elements of input in the dimension dim.

For example, if input is a vector of size N, the result will also be a vector of size N, with elements.

yi=x1×x2×x3×⋯×xiy_i = x_1 \times x_2\times x_3\times \dots \times x_i yi=x1×x2×x3×⋯×xi

Parameters

input (Tensor) – the input tensor.
dim (int) – the dimension to do the operation over
dtype (torch.dtype, optional) – the desired data type of returned tensor. If specified, the input tensor is casted to dtype before the operation is performed. This is useful for preventing data type overflows. Default: None.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(10)
>>> a
tensor([ 0.6001,  0.2069, -0.1919,  0.9792,  0.6727,  1.0062,  0.4126,
        -0.2129, -0.4206,  0.1968])
>>> torch.cumprod(a, dim=0)
tensor([ 0.6001,  0.1241, -0.0238, -0.0233, -0.0157, -0.0158, -0.0065,
         0.0014, -0.0006, -0.0001])

>>> a[5] = 0.0
>>> torch.cumprod(a, dim=0)
tensor([ 0.6001,  0.1241, -0.0238, -0.0233, -0.0157, -0.0000, -0.0000,
         0.0000, -0.0000, -0.0000])

`torch.cumsum`(input, dim, out=None, dtype=None) → Tensor

Returns the cumulative sum of elements of input in the dimension dim.

For example, if input is a vector of size N, the result will also be a vector of size N, with elements.

yi=x1+x2+x3+⋯+xiy_i = x_1 + x_2 + x_3 + \dots + x_i yi=x1+x2+x3+⋯+xi

Parameters

input (Tensor) – the input tensor.
dim (int) – the dimension to do the operation over
dtype (torch.dtype, optional) – the desired data type of returned tensor. If specified, the input tensor is casted to dtype before the operation is performed. This is useful for preventing data type overflows. Default: None.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(10)
>>> a
tensor([-0.8286, -0.4890,  0.5155,  0.8443,  0.1865, -0.1752, -2.0595,
         0.1850, -1.1571, -0.4243])
>>> torch.cumsum(a, dim=0)
tensor([-0.8286, -1.3175, -0.8020,  0.0423,  0.2289,  0.0537, -2.0058,
        -1.8209, -2.9780, -3.4022])

`torch.dist`(input, other, p=2) → Tensor

Returns the p-norm of (input - other)

The shapes of input and other must be broadcastable.

Parameters

input (Tensor) – the input tensor.
other (Tensor) – the Right-hand-side input tensor
p (float, optional) – the norm to be computed

Example:

>>> x = torch.randn(4)
>>> x
tensor([-1.5393, -0.8675,  0.5916,  1.6321])
>>> y = torch.randn(4)
>>> y
tensor([ 0.0967, -1.0511,  0.6295,  0.8360])
>>> torch.dist(x, y, 3.5)
tensor(1.6727)
>>> torch.dist(x, y, 3)
tensor(1.6973)
>>> torch.dist(x, y, 0)
tensor(inf)
>>> torch.dist(x, y, 1)
tensor(2.6537)

`torch.logsumexp`(input, dim, keepdim=False, out=None)

Returns the log of summed exponentials of each row of the input tensor in the given dimension dim. The computation is numerically stabilized.

For summation index jjj given by dim and other indices iii , the result is

logsumexp(x)i=log⁡∑jexp⁡(xij)\text{logsumexp}(x)_{i} = \log \sum_j \exp(x_{ij}) logsumexp(x)i=logj∑exp(xij)

If keepdim is True, the output tensor is of the same size as input except in the dimension(s) dim where it is of size 1. Otherwise, dim is squeezed (see torch.squeeze()), resulting in the output tensor having 1 (or len(dim)) fewer dimension(s).

Parameters

input (Tensor) – the input tensor.
dim (int or tuple of python:ints) – the dimension or dimensions to reduce.
keepdim (bool) – whether the output tensor has dim retained or not.
out (Tensor, optional) – the output tensor.

Example::

>>> a = torch.randn(3, 3)
>>> torch.logsumexp(a, 1)
tensor([ 0.8442,  1.4322,  0.8711])

`torch.mean`()

torch.mean(input) → Tensor

Returns the mean value of all elements in the input tensor.

Parameters

input (Tensor) – the input tensor.

Example:

>>> a = torch.randn(1, 3)
>>> a
tensor([[ 0.2294, -0.5481,  1.3288]])
>>> torch.mean(a)
tensor(0.3367)

`torch.mean`(input, dim, keepdim=False, out=None) → Tensor

Returns the mean value of each row of the input tensor in the given dimension dim. If dim is a list of dimensions, reduce over all of them.

Parameters

input (Tensor) – the input tensor.
dim (int or tuple of python:ints) – the dimension or dimensions to reduce.
keepdim (bool) – whether the output tensor has dim retained or not.
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[-0.3841,  0.6320,  0.4254, -0.7384],
        [-0.9644,  1.0131, -0.6549, -1.4279],
        [-0.2951, -1.3350, -0.7694,  0.5600],
        [ 1.0842, -0.9580,  0.3623,  0.2343]])
>>> torch.mean(a, 1)
tensor([-0.0163, -0.5085, -0.4599,  0.1807])
>>> torch.mean(a, 1, True)
tensor([[-0.0163],
        [-0.5085],
        [-0.4599],
        [ 0.1807]])

`torch.median`()

torch.median(input) → Tensor

Returns the median value of all elements in the input tensor.

Parameters

input (Tensor) – the input tensor.

Example:

>>> a = torch.randn(1, 3)
>>> a
tensor([[ 1.5219, -1.5212,  0.2202]])
>>> torch.median(a)
tensor(0.2202)

`torch.median`(input, dim=-1, keepdim=False, values=None, indices=None) -> (Tensor, LongTensor)

Returns a namedtuple (values, indices) where values is the median value of each row of the input tensor in the given dimension dim. And indices is the index location of each median value found.

By default, dim is the last dimension of the input tensor.

If keepdim is True, the output tensors are of the same size as input except in the dimension dim where they are of size 1. Otherwise, dim is squeezed (see torch.squeeze()), resulting in the outputs tensor having 1 fewer dimension than input.

Parameters

input (Tensor) – the input tensor.
dim (int) – the dimension to reduce.
keepdim (bool) – whether the output tensor has dim retained or not.
values (Tensor, optional) – the output tensor
indices (Tensor, optional) – the output index tensor

Example:

>>> a = torch.randn(4, 5)
>>> a
tensor([[ 0.2505, -0.3982, -0.9948,  0.3518, -1.3131],
        [ 0.3180, -0.6993,  1.0436,  0.0438,  0.2270],
        [-0.2751,  0.7303,  0.2192,  0.3321,  0.2488],
        [ 1.0778, -1.9510,  0.7048,  0.4742, -0.7125]])
>>> torch.median(a, 1)
torch.return_types.median(values=tensor([-0.3982,  0.2270,  0.2488,  0.4742]), indices=tensor([1, 4, 4, 3]))

`torch.mode`(input, dim=-1, keepdim=False, values=None, indices=None) -> (Tensor, LongTensor)

Returns a namedtuple (values, indices) where values is the mode value of each row of the input tensor in the given dimension dim, i.e. a value which appears most often in that row, and indices is the index location of each mode value found.

By default, dim is the last dimension of the input tensor.

Note

This function is not defined for torch.cuda.Tensor yet.

Parameters

input (Tensor) – the input tensor.
dim (int) – the dimension to reduce.
keepdim (bool) – whether the output tensor has dim retained or not.
values (Tensor, optional) – the output tensor
indices (Tensor, optional) – the output index tensor

Example:

>>> a = torch.randint(10, (5,))
>>> a
tensor([6, 5, 1, 0, 2])
>>> b = a + (torch.randn(50, 1) * 5).long()
>>> torch.mode(b, 0)
torch.return_types.mode(values=tensor([6, 5, 1, 0, 2]), indices=tensor([2, 2, 2, 2, 2]))

`torch.norm`(input, p='fro', dim=None, keepdim=False, out=None, dtype=None)[source]

Returns the matrix norm or vector norm of a given tensor.

Parameters

input (Tensor) – the input tensor
p (int, float, inf, -inf, 'fro', 'nuc', optional) – the order of norm. Default: 'fro' The following norms can be calculated: ord matrix norm vector norm None Frobenius norm 2-norm ’fro’ Frobenius norm – ‘nuc’ nuclear norm – Other as vec norm when dim is None sum(abs(x)**ord)**(1./ord)
dim (int, 2-tuple of python:ints, 2-list of python:ints, optional) – If it is an int, vector norm will be calculated, if it is 2-tuple of ints, matrix norm will be calculated. If the value is None, matrix norm will be calculated when the input tensor only has two dimensions, vector norm will be calculated when the input tensor only has one dimension. If the input tensor has more than two dimensions, the vector norm will be applied to last dimension.
keepdim (bool, optional) – whether the output tensors have dim retained or not. Ignored if dim = None and out = None. Default: False
out (Tensor, optional) – the output tensor. Ignored if dim = None and out = None.
dtype (torch.dtype, optional) – the desired data type of returned tensor. If specified, the input tensor is casted to :attr:’dtype’ while performing the operation. Default: None.

Example:

>>> import torch
>>> a = torch.arange(9, dtype= torch.float) - 4
>>> b = a.reshape((3, 3))
>>> torch.norm(a)
tensor(7.7460)
>>> torch.norm(b)
tensor(7.7460)
>>> torch.norm(a, float('inf'))
tensor(4.)
>>> torch.norm(b, float('inf'))
tensor(4.)
>>> c = torch.tensor([[ 1, 2, 3],[-1, 1, 4]] , dtype= torch.float)
>>> torch.norm(c, dim=0)
tensor([1.4142, 2.2361, 5.0000])
>>> torch.norm(c, dim=1)
tensor([3.7417, 4.2426])
>>> torch.norm(c, p=1, dim=1)
tensor([6., 6.])
>>> d = torch.arange(8, dtype= torch.float).reshape(2,2,2)
>>> torch.norm(d, dim=(1,2))
tensor([ 3.7417, 11.2250])
>>> torch.norm(d[0, :, :]), torch.norm(d[1, :, :])
(tensor(3.7417), tensor(11.2250))

`torch.prod`()

torch.prod(input, dtype=None) → Tensor

Returns the product of all elements in the input tensor.

Parameters

input (Tensor) – the input tensor.
dtype (torch.dtype, optional) – the desired data type of returned tensor. If specified, the input tensor is casted to dtype before the operation is performed. This is useful for preventing data type overflows. Default: None.

Example:

>>> a = torch.randn(1, 3)
>>> a
tensor([[-0.8020,  0.5428, -1.5854]])
>>> torch.prod(a)
tensor(0.6902)

`torch.prod`(input, dim, keepdim=False, dtype=None) → Tensor

Returns the product of each row of the input tensor in the given dimension dim.

If keepdim is True, the output tensor is of the same size as input except in the dimension dim where it is of size 1. Otherwise, dim is squeezed (see torch.squeeze()), resulting in the output tensor having 1 fewer dimension than input.

Parameters

input (Tensor) – the input tensor.
dim (int) – the dimension to reduce.
keepdim (bool) – whether the output tensor has dim retained or not.
dtype (torch.dtype, optional) – the desired data type of returned tensor. If specified, the input tensor is casted to dtype before the operation is performed. This is useful for preventing data type overflows. Default: None.

Example:

>>> a = torch.randn(4, 2)
>>> a
tensor([[ 0.5261, -0.3837],
        [ 1.1857, -0.2498],
        [-1.1646,  0.0705],
        [ 1.1131, -1.0629]])
>>> torch.prod(a, 1)
tensor([-0.2018, -0.2962, -0.0821, -1.1831])

`torch.std`()

torch.std(input, unbiased=True) → Tensor

Returns the standard-deviation of all elements in the input tensor.

If unbiased is False, then the standard-deviation will be calculated via the biased estimator. Otherwise, Bessel’s correction will be used.

Parameters

input (Tensor) – the input tensor.
unbiased (bool) – whether to use the unbiased estimation or not

Example:

>>> a = torch.randn(1, 3)
>>> a
tensor([[-0.8166, -1.3802, -0.3560]])
>>> torch.std(a)
tensor(0.5130)

`torch.std`(input, dim, keepdim=False, unbiased=True, out=None) → Tensor

Returns the standard-deviation of each row of the input tensor in the dimension dim. If dim is a list of dimensions, reduce over all of them.

If unbiased is False, then the standard-deviation will be calculated via the biased estimator. Otherwise, Bessel’s correction will be used.

Parameters

input (Tensor) – the input tensor.
dim (int or tuple of python:ints) – the dimension or dimensions to reduce.
keepdim (bool) – whether the output tensor has dim retained or not.
unbiased (bool) – whether to use the unbiased estimation or not
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[ 0.2035,  1.2959,  1.8101, -0.4644],
        [ 1.5027, -0.3270,  0.5905,  0.6538],
        [-1.5745,  1.3330, -0.5596, -0.6548],
        [ 0.1264, -0.5080,  1.6420,  0.1992]])
>>> torch.std(a, dim=1)
tensor([ 1.0311,  0.7477,  1.2204,  0.9087])

`torch.std_mean`()

torch.std_mean(input, unbiased=True) -> (Tensor, Tensor)

Returns the standard-deviation and mean of all elements in the input tensor.

If unbiased is False, then the standard-deviation will be calculated via the biased estimator. Otherwise, Bessel’s correction will be used.

Parameters

input (Tensor) – the input tensor.
unbiased (bool) – whether to use the unbiased estimation or not

Example:

>>> a = torch.randn(1, 3)
>>> a
tensor([[0.3364, 0.3591, 0.9462]])
>>> torch.std_mean(a)
(tensor(0.3457), tensor(0.5472))

`torch.std`(input, dim, keepdim=False, unbiased=True) -> (Tensor, Tensor)

Returns the standard-deviation and mean of each row of the input tensor in the dimension dim. If dim is a list of dimensions, reduce over all of them.

If unbiased is False, then the standard-deviation will be calculated via the biased estimator. Otherwise, Bessel’s correction will be used.

Parameters

input (Tensor) – the input tensor.
dim (int or tuple of python:ints) – the dimension or dimensions to reduce.
keepdim (bool) – whether the output tensor has dim retained or not.
unbiased (bool) – whether to use the unbiased estimation or not

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[ 0.5648, -0.5984, -1.2676, -1.4471],
        [ 0.9267,  1.0612,  1.1050, -0.6014],
        [ 0.0154,  1.9301,  0.0125, -1.0904],
        [-1.9711, -0.7748, -1.3840,  0.5067]])
>>> torch.std_mean(a, 1)
(tensor([0.9110, 0.8197, 1.2552, 1.0608]), tensor([-0.6871,  0.6229,  0.2169, -0.9058]))

`torch.sum`()

torch.sum(input, dtype=None) → Tensor

Returns the sum of all elements in the input tensor.

Parameters

input (Tensor) – the input tensor.
dtype (torch.dtype, optional) – the desired data type of returned tensor. If specified, the input tensor is casted to dtype before the operation is performed. This is useful for preventing data type overflows. Default: None.

Example:

>>> a = torch.randn(1, 3)
>>> a
tensor([[ 0.1133, -0.9567,  0.2958]])
>>> torch.sum(a)
tensor(-0.5475)

`torch.sum`(input, dim, keepdim=False, dtype=None) → Tensor

Returns the sum of each row of the input tensor in the given dimension dim. If dim is a list of dimensions, reduce over all of them.

Parameters

input (Tensor) – the input tensor.
dim (int or tuple of python:ints) – the dimension or dimensions to reduce.
keepdim (bool) – whether the output tensor has dim retained or not.
dtype (torch.dtype, optional) – the desired data type of returned tensor. If specified, the input tensor is casted to dtype before the operation is performed. This is useful for preventing data type overflows. Default: None.

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[ 0.0569, -0.2475,  0.0737, -0.3429],
        [-0.2993,  0.9138,  0.9337, -1.6864],
        [ 0.1132,  0.7892, -0.1003,  0.5688],
        [ 0.3637, -0.9906, -0.4752, -1.5197]])
>>> torch.sum(a, 1)
tensor([-0.4598, -0.1381,  1.3708, -2.6217])
>>> b = torch.arange(4 * 5 * 6).view(4, 5, 6)
>>> torch.sum(b, (2, 1))
tensor([  435.,  1335.,  2235.,  3135.])

`torch.unique`(input, sorted=True, return_inverse=False, return_counts=False, dim=None)[source]

Returns the unique elements of the input tensor.

Parameters

input (Tensor) – the input tensor
sorted (bool) – Whether to sort the unique elements in ascending order before returning as output.
return_inverse (bool) – Whether to also return the indices for where elements in the original input ended up in the returned unique list.
return_counts (bool) – Whether to also return the counts for each unique element.
dim (int) – the dimension to apply unique. If None, the unique of the flattened input is returned. default: None

Returns

A tensor or a tuple of tensors containing

output (Tensor): the output list of unique scalar elements.
inverse_indices (Tensor): (optional) if return_inverse is True, there will be an additional returned tensor (same shape as input) representing the indices for where elements in the original input map to in the output; otherwise, this function will only return a single tensor.
counts (Tensor): (optional) if return_counts is True, there will be an additional returned tensor (same shape as output or output.size(dim), if dim was specified) representing the number of occurrences for each unique value or tensor.

Return type

(Tensor, Tensor (optional), Tensor (optional))

Example:

>>> output = torch.unique(torch.tensor([1, 3, 2, 3], dtype=torch.long))
>>> output
tensor([ 2,  3,  1])

>>> output, inverse_indices = torch.unique(
        torch.tensor([1, 3, 2, 3], dtype=torch.long), sorted=True, return_inverse=True)
>>> output
tensor([ 1,  2,  3])
>>> inverse_indices
tensor([ 0,  2,  1,  2])

>>> output, inverse_indices = torch.unique(
        torch.tensor([[1, 3], [2, 3]], dtype=torch.long), sorted=True, return_inverse=True)
>>> output
tensor([ 1,  2,  3])
>>> inverse_indices
tensor([[ 0,  2],
        [ 1,  2]])

`torch.unique_consecutive`(input, return_inverse=False, return_counts=False, dim=None)[source]

Eliminates all but the first element from every consecutive group of equivalent elements.

Note

This function is different from torch.unique() in the sense that this function only eliminates consecutive duplicate values. This semantics is similar to std::unique in C++.

Parameters

input (Tensor) – the input tensor
return_inverse (bool) – Whether to also return the indices for where elements in the original input ended up in the returned unique list.
return_counts (bool) – Whether to also return the counts for each unique element.
dim (int) – the dimension to apply unique. If None, the unique of the flattened input is returned. default: None

Returns

A tensor or a tuple of tensors containing

output (Tensor): the output list of unique scalar elements.
inverse_indices (Tensor): (optional) if return_inverse is True, there will be an additional returned tensor (same shape as input) representing the indices for where elements in the original input map to in the output; otherwise, this function will only return a single tensor.
counts (Tensor): (optional) if return_counts is True, there will be an additional returned tensor (same shape as output or output.size(dim), if dim was specified) representing the number of occurrences for each unique value or tensor.

Return type

(Tensor, Tensor (optional), Tensor (optional))

Example:

>>> x = torch.tensor([1, 1, 2, 2, 3, 1, 1, 2])
>>> output = torch.unique_consecutive(x)
>>> output
tensor([1, 2, 3, 1, 2])

>>> output, inverse_indices = torch.unique_consecutive(x, return_inverse=True)
>>> output
tensor([1, 2, 3, 1, 2])
>>> inverse_indices
tensor([0, 0, 1, 1, 2, 3, 3, 4])

>>> output, counts = torch.unique_consecutive(x, return_counts=True)
>>> output
tensor([1, 2, 3, 1, 2])
>>> counts
tensor([2, 2, 1, 2, 1])

`torch.var`()

torch.var(input, unbiased=True) → Tensor

Returns the variance of all elements in the input tensor.

If unbiased is False, then the variance will be calculated via the biased estimator. Otherwise, Bessel’s correction will be used.

Parameters

input (Tensor) – the input tensor.
unbiased (bool) – whether to use the unbiased estimation or not

Example:

>>> a = torch.randn(1, 3)
>>> a
tensor([[-0.3425, -1.2636, -0.4864]])
>>> torch.var(a)
tensor(0.2455)

`torch.var`(input, dim, keepdim=False, unbiased=True, out=None) → Tensor

Returns the variance of each row of the input tensor in the given dimension dim.

If unbiased is False, then the variance will be calculated via the biased estimator. Otherwise, Bessel’s correction will be used.

Parameters

input (Tensor) – the input tensor.
dim (int or tuple of python:ints) – the dimension or dimensions to reduce.
keepdim (bool) – whether the output tensor has dim retained or not.
unbiased (bool) – whether to use the unbiased estimation or not
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[-0.3567,  1.7385, -1.3042,  0.7423],
        [ 1.3436, -0.1015, -0.9834, -0.8438],
        [ 0.6056,  0.1089, -0.3112, -1.4085],
        [-0.7700,  0.6074, -0.1469,  0.7777]])
>>> torch.var(a, 1)
tensor([ 1.7444,  1.1363,  0.7356,  0.5112])

`torch.var_mean`()

torch.var_mean(input, unbiased=True) -> (Tensor, Tensor)

Returns the variance and mean of all elements in the input tensor.

If unbiased is False, then the variance will be calculated via the biased estimator. Otherwise, Bessel’s correction will be used.

Parameters

input (Tensor) – the input tensor.
unbiased (bool) – whether to use the unbiased estimation or not

Example:

>>> a = torch.randn(1, 3)
>>> a
tensor([[0.0146, 0.4258, 0.2211]])
>>> torch.var_mean(a)
(tensor(0.0423), tensor(0.2205))

`torch.var_mean`(input, dim, keepdim=False, unbiased=True) -> (Tensor, Tensor)

Returns the variance and mean of each row of the input tensor in the given dimension dim.

If unbiased is False, then the variance will be calculated via the biased estimator. Otherwise, Bessel’s correction will be used.

Parameters

input (Tensor) – the input tensor.
dim (int or tuple of python:ints) – the dimension or dimensions to reduce.
keepdim (bool) – whether the output tensor has dim retained or not.
unbiased (bool) – whether to use the unbiased estimation or not

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[-1.5650,  2.0415, -0.1024, -0.5790],
        [ 0.2325, -2.6145, -1.6428, -0.3537],
        [-0.2159, -1.1069,  1.2882, -1.3265],
        [-0.6706, -1.5893,  0.6827,  1.6727]])
>>> torch.var_mean(a, 1)
(tensor([2.3174, 1.6403, 1.4092, 2.0791]), tensor([-0.0512, -1.0946, -0.3403,  0.0239]))

Comparison Ops

`torch.allclose`(input, other, rtol=1e-05, atol=1e-08, equal_nan=False) → bool

This function checks if all input and other satisfy the condition:

∣input−other∣≤atol+rtol×∣other∣\lvert \text{input} - \text{other} \rvert \leq \texttt{atol} + \texttt{rtol} \times \lvert \text{other} \rvert ∣input−other∣≤atol+rtol×∣other∣

elementwise, for all elements of input and other. The behaviour of this function is analogous to numpy.allclose

Parameters

input (Tensor) – first tensor to compare
other (Tensor) – second tensor to compare
atol (float, optional) – absolute tolerance. Default: 1e-08
rtol (float, optional) – relative tolerance. Default: 1e-05
equal_nan (bool, optional) – if True, then two NaN s will be compared as equal. Default: False

Example:

>>> torch.allclose(torch.tensor([10000., 1e-07]), torch.tensor([10000.1, 1e-08]))
False
>>> torch.allclose(torch.tensor([10000., 1e-08]), torch.tensor([10000.1, 1e-09]))
True
>>> torch.allclose(torch.tensor([1.0, float('nan')]), torch.tensor([1.0, float('nan')]))
False
>>> torch.allclose(torch.tensor([1.0, float('nan')]), torch.tensor([1.0, float('nan')]), equal_nan=True)
True

`torch.argsort`(input, dim=-1, descending=False, out=None) → LongTensor

Returns the indices that sort a tensor along a given dimension in ascending order by value.

This is the second value returned by torch.sort(). See its documentation for the exact semantics of this method.

Parameters

input (Tensor) – the input tensor.
dim (int, optional) – the dimension to sort along
descending (bool, optional) – controls the sorting order (ascending or descending)

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[ 0.0785,  1.5267, -0.8521,  0.4065],
        [ 0.1598,  0.0788, -0.0745, -1.2700],
        [ 1.2208,  1.0722, -0.7064,  1.2564],
        [ 0.0669, -0.2318, -0.8229, -0.9280]])


>>> torch.argsort(a, dim=1)
tensor([[2, 0, 3, 1],
        [3, 2, 1, 0],
        [2, 1, 0, 3],
        [3, 2, 1, 0]])

`torch.eq`(input, other, out=None) → Tensor

Computes element-wise equality

The second argument can be a number or a tensor whose shape is broadcastable with the first argument.

Parameters

input (Tensor) – the tensor to compare
other (Tensor or float) – the tensor or value to compare
out (Tensor, optional) – the output tensor. Must be a ByteTensor

Returns

A torch.BoolTensor containing a True at each location where comparison is true

Return type

Tensor

Example:

>>> torch.eq(torch.tensor([[1, 2], [3, 4]]), torch.tensor([[1, 1], [4, 4]]))
tensor([[ 1,  0],
        [ 0,  1]], dtype=torch.uint8)

`torch.equal`(input, other) → bool

True if two tensors have the same size and elements, False otherwise.

Example:

>>> torch.equal(torch.tensor([1, 2]), torch.tensor([1, 2]))
True

`torch.ge`(input, other, out=None) → Tensor

Computes input≥other\text{input} \geq \text{other}input≥other element-wise.

The second argument can be a number or a tensor whose shape is broadcastable with the first argument.

Parameters

input (Tensor) – the tensor to compare
other (Tensor or float) – the tensor or value to compare
out (Tensor, optional) – the output tensor that must be a BoolTensor

Returns

A torch.BoolTensor containing a True at each location where comparison is true

Return type

Tensor

Example:

>>> torch.ge(torch.tensor([[1, 2], [3, 4]]), torch.tensor([[1, 1], [4, 4]]))
tensor([[True, True], [False, True]])

`torch.gt`(input, other, out=None) → Tensor

Computes input>other\text{input} > \text{other}input>other element-wise.

The second argument can be a number or a tensor whose shape is broadcastable with the first argument.

Parameters

input (Tensor) – the tensor to compare
other (Tensor or float) – the tensor or value to compare
out (Tensor, optional) – the output tensor that must be a BoolTensor

Returns

A torch.BoolTensor containing a True at each location where comparison is true

Return type

Tensor

Example:

>>> torch.gt(torch.tensor([[1, 2], [3, 4]]), torch.tensor([[1, 1], [4, 4]]))
tensor([[False, True], [False, False]])

`torch.isfinite`(tensor)[source]

Returns a new tensor with boolean elements representing if each element is Finite or not.

Parameters

tensor (Tensor) – A tensor to check

Returns

A torch.Tensor with dtype torch.bool containing a True at each location of finite elements and False otherwise

Return type

Tensor

Example:

>>> torch.isfinite(torch.tensor([1, float('inf'), 2, float('-inf'), float('nan')]))
tensor([True,  False,  True,  False,  False])

`torch.isinf`(tensor)[source]

Returns a new tensor with boolean elements representing if each element is +/-INF or not.

Parameters

tensor (Tensor) – A tensor to check

Returns

A torch.Tensor with dtype torch.bool containing a True at each location of +/-INF elements and False otherwise

Return type

Tensor

Example:

>>> torch.isinf(torch.tensor([1, float('inf'), 2, float('-inf'), float('nan')]))
tensor([False,  True,  False,  True,  False])

`torch.isnan`()

Returns a new tensor with boolean elements representing if each element is NaN or not.

Parameters

input (Tensor) – A tensor to check

Returns

A torch.BoolTensor containing a True at each location of NaN elements.

Return type

Tensor

Example:

>>> torch.isnan(torch.tensor([1, float('nan'), 2]))
tensor([False, True, False])

`torch.kthvalue`(input, k, dim=None, keepdim=False, out=None) -> (Tensor, LongTensor)

Returns a namedtuple (values, indices) where values is the k th smallest element of each row of the input tensor in the given dimension dim. And indices is the index location of each element found.

If dim is not given, the last dimension of the input is chosen.

If keepdim is True, both the values and indices tensors are the same size as input, except in the dimension dim where they are of size 1. Otherwise, dim is squeezed (see torch.squeeze()), resulting in both the values and indices tensors having 1 fewer dimension than the input tensor.

Parameters

input (Tensor) – the input tensor.
k (int) – k for the k-th smallest element
dim (int, optional) – the dimension to find the kth value along
keepdim (bool) – whether the output tensor has dim retained or not.
out (tuple, optional) – the output tuple of (Tensor, LongTensor) can be optionally given to be used as output buffers

Example:

>>> x = torch.arange(1., 6.)
>>> x
tensor([ 1.,  2.,  3.,  4.,  5.])
>>> torch.kthvalue(x, 4)
torch.return_types.kthvalue(values=tensor(4.), indices=tensor(3))

>>> x=torch.arange(1.,7.).resize_(2,3)
>>> x
tensor([[ 1.,  2.,  3.],
        [ 4.,  5.,  6.]])
>>> torch.kthvalue(x, 2, 0, True)
torch.return_types.kthvalue(values=tensor([[4., 5., 6.]]), indices=tensor([[1, 1, 1]]))

`torch.le`(input, other, out=None) → Tensor

Computes input≤other\text{input} \leq \text{other}input≤other element-wise.

The second argument can be a number or a tensor whose shape is broadcastable with the first argument.

Parameters

input (Tensor) – the tensor to compare
other (Tensor or float) – the tensor or value to compare
out (Tensor, optional) – the output tensor that must be a BoolTensor

Returns

A torch.BoolTensor containing a True at each location where comparison is true

Return type

Tensor

Example:

>>> torch.le(torch.tensor([[1, 2], [3, 4]]), torch.tensor([[1, 1], [4, 4]]))
tensor([[True, False], [True, True]])

`torch.lt`(input, other, out=None) → Tensor

Computes input<other\text{input} < \text{other}input<other element-wise.

The second argument can be a number or a tensor whose shape is broadcastable with the first argument.

Parameters

input (Tensor) – the tensor to compare
other (Tensor or float) – the tensor or value to compare
out (Tensor, optional) – the output tensor that must be a BoolTensor

Returns

A torch.BoolTensor containing a True at each location where comparison is true

Return type

Tensor

Example:

>>> torch.lt(torch.tensor([[1, 2], [3, 4]]), torch.tensor([[1, 1], [4, 4]]))
tensor([[False, False], [True, False]])

`torch.max`()

torch.max(input) → Tensor

Returns the maximum value of all elements in the input tensor.

Parameters

{input} –

Example:

>>> a = torch.randn(1, 3)
>>> a
tensor([[ 0.6763,  0.7445, -2.2369]])
>>> torch.max(a)
tensor(0.7445)

`torch.max`(input, dim, keepdim=False, out=None) -> (Tensor, LongTensor)

Returns a namedtuple (values, indices) where values is the maximum value of each row of the input tensor in the given dimension dim. And indices is the index location of each maximum value found (argmax).

Parameters

{input} –
{dim} –
Default ({keepdim}) – False.
out (tuple, optional) – the result tuple of two output tensors (max, max_indices)

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[-1.2360, -0.2942, -0.1222,  0.8475],
        [ 1.1949, -1.1127, -2.2379, -0.6702],
        [ 1.5717, -0.9207,  0.1297, -1.8768],
        [-0.6172,  1.0036, -0.6060, -0.2432]])
>>> torch.max(a, 1)
torch.return_types.max(values=tensor([0.8475, 1.1949, 1.5717, 1.0036]), indices=tensor([3, 0, 0, 1]))

`torch.max`(input, other, out=None) → Tensor

Each element of the tensor input is compared with the corresponding element of the tensor other and an element-wise maximum is taken.

The shapes of input and other don’t need to match, but they must be broadcastable.

outi=max⁡(tensori,otheri)\text{out}_i = \max(\text{tensor}_i, \text{other}_i) outi=max(tensori,otheri)

Note

When the shapes do not match, the shape of the returned output tensor follows the broadcasting rules.

Parameters

input (Tensor) – the input tensor.
other (Tensor) – the second input tensor
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.2942, -0.7416,  0.2653, -0.1584])
>>> b = torch.randn(4)
>>> b
tensor([ 0.8722, -1.7421, -0.4141, -0.5055])
>>> torch.max(a, b)
tensor([ 0.8722, -0.7416,  0.2653, -0.1584])

`torch.min`()

torch.min(input) → Tensor

Returns the minimum value of all elements in the input tensor.

Parameters

{input} –

Example:

>>> a = torch.randn(1, 3)
>>> a
tensor([[ 0.6750,  1.0857,  1.7197]])
>>> torch.min(a)
tensor(0.6750)

`torch.min`(input, dim, keepdim=False, out=None) -> (Tensor, LongTensor)

Returns a namedtuple (values, indices) where values is the minimum value of each row of the input tensor in the given dimension dim. And indices is the index location of each minimum value found (argmin).

Parameters

{input} –
{dim} –
{keepdim} –
out (tuple, optional) – the tuple of two output tensors (min, min_indices)

Example:

>>> a = torch.randn(4, 4)
>>> a
tensor([[-0.6248,  1.1334, -1.1899, -0.2803],
        [-1.4644, -0.2635, -0.3651,  0.6134],
        [ 0.2457,  0.0384,  1.0128,  0.7015],
        [-0.1153,  2.9849,  2.1458,  0.5788]])
>>> torch.min(a, 1)
torch.return_types.min(values=tensor([-1.1899, -1.4644,  0.0384, -0.1153]), indices=tensor([2, 0, 1, 0]))

`torch.min`(input, other, out=None) → Tensor

Each element of the tensor input is compared with the corresponding element of the tensor other and an element-wise minimum is taken. The resulting tensor is returned.

The shapes of input and other don’t need to match, but they must be broadcastable.

outi=min⁡(tensori,otheri)\text{out}_i = \min(\text{tensor}_i, \text{other}_i) outi=min(tensori,otheri)

Note

When the shapes do not match, the shape of the returned output tensor follows the broadcasting rules.

Parameters

input (Tensor) – the input tensor.
other (Tensor) – the second input tensor
out (Tensor, optional) – the output tensor.

Example:

>>> a = torch.randn(4)
>>> a
tensor([ 0.8137, -1.1740, -0.6460,  0.6308])
>>> b = torch.randn(4)
>>> b
tensor([-0.1369,  0.1555,  0.4019, -0.1929])
>>> torch.min(a, b)
tensor([-0.1369, -1.1740, -0.6460, -0.1929])

`torch.ne`(input, other, out=None) → Tensor

Computes input≠otherinput \neq otherinput=other element-wise.

The second argument can be a number or a tensor whose shape is broadcastable with the first argument.

Parameters

input (Tensor) – the tensor to compare
other (Tensor or float) – the tensor or value to compare
out (Tensor, optional) – the output tensor that must be a BoolTensor

Returns

A torch.BoolTensor containing a True at each location where comparison is true.

Return type

Tensor

Example:

>>> torch.ne(torch.tensor([[1, 2], [3, 4]]), torch.tensor([[1, 1], [4, 4]]))
tensor([[False, True], [True, False]])

`torch.sort`(input, dim=-1, descending=False, out=None) -> (Tensor, LongTensor)

Sorts the elements of the input tensor along a given dimension in ascending order by value.

If dim is not given, the last dimension of the input is chosen.

If descending is True then the elements are sorted in descending order by value.

A namedtuple of (values, indices) is returned, where the values are the sorted values and indices are the indices of the elements in the original input tensor.

Parameters

input (Tensor) – the input tensor.
dim (int, optional) – the dimension to sort along
descending (bool, optional) – controls the sorting order (ascending or descending)
out (tuple, optional) – the output tuple of (Tensor, LongTensor) that can be optionally given to be used as output buffers

Example:

>>> x = torch.randn(3, 4)
>>> sorted, indices = torch.sort(x)
>>> sorted
tensor([[-0.2162,  0.0608,  0.6719,  2.3332],
        [-0.5793,  0.0061,  0.6058,  0.9497],
        [-0.5071,  0.3343,  0.9553,  1.0960]])
>>> indices
tensor([[ 1,  0,  2,  3],
        [ 3,  1,  0,  2],
        [ 0,  3,  1,  2]])

>>> sorted, indices = torch.sort(x, 0)
>>> sorted
tensor([[-0.5071, -0.2162,  0.6719, -0.5793],
        [ 0.0608,  0.0061,  0.9497,  0.3343],
        [ 0.6058,  0.9553,  1.0960,  2.3332]])
>>> indices
tensor([[ 2,  0,  0,  1],
        [ 0,  1,  1,  2],
        [ 1,  2,  2,  0]])

`torch.topk`(input, k, dim=None, largest=True, sorted=True, out=None) -> (Tensor, LongTensor)

Returns the k largest elements of the given input tensor along a given dimension.

If dim is not given, the last dimension of the input is chosen.

If largest is False then the k smallest elements are returned.

A namedtuple of (values, indices) is returned, where the indices are the indices of the elements in the original input tensor.

The boolean option sorted if True, will make sure that the returned k elements are themselves sorted

Parameters

input (Tensor) – the input tensor.
k (int) – the k in “top-k”
dim (int, optional) – the dimension to sort along
largest (bool, optional) – controls whether to return largest or smallest elements
sorted (bool, optional) – controls whether to return the elements in sorted order
out (tuple, optional) – the output tuple of (Tensor, LongTensor) that can be optionally given to be used as output buffers

Example:

>>> x = torch.arange(1., 6.)
>>> x
tensor([ 1.,  2.,  3.,  4.,  5.])
>>> torch.topk(x, 3)
torch.return_types.topk(values=tensor([5., 4., 3.]), indices=tensor([4, 3, 2]))

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