Central to torch is the torch_tensor objects.
torch_tensor’s are R objects very similar to R6 instances.
Tensors have a large amount of methods that can be called using the
$ operator.
Following is a list of all methods that can be called by tensor objects and their documentation. You can also look at PyTorch’s documentation for additional details.
numpy_T
Is this Tensor with its dimensions reversed.
If n is the number of dimensions in x,
x$numpy_T() is equivalent to
x$permute(n, n-1, ..., 1).
add
add(other, *, alpha=1) -> Tensor
Add a scalar or tensor to self tensor. If both
alpha and other are specified, each element of
other is scaled by alpha before being
used.
When other is a tensor, the shape of other
must be broadcastable with the shape of the underlying tensor
See ?torch_add
align_as
align_as(other) -> Tensor
Permutes the dimensions of the self tensor to match the
dimension order in the other tensor, adding size-one dims
for any new names.
This operation is useful for explicit broadcasting by names (see examples).
All of the dims of self must be named in order to use
this method. The resulting tensor is a view on the original tensor.
All dimension names of self must be present in
other$names. other may contain named
dimensions that are not in self$names; the output tensor
has a size-one dimension for each of those new names.
To align a tensor to a specific order, use
$align_to.
Examples:
# Example 1: Applying a mask
mask <- torch_randint(low = 0, high = 2, size = c(127, 128), dtype=torch_bool())$refine_names(c('W', 'H'))
imgs <- torch_randn(32, 128, 127, 3, names=c('N', 'H', 'W', 'C'))
imgs$masked_fill_(mask$align_as(imgs), 0)
# Example 2: Applying a per-channel-scale
scale_channels <- function(input, scale) {
scale <- scale$refine_names("C")
input * scale$align_as(input)
}
num_channels <- 3
scale <- torch_randn(num_channels, names='C')
imgs <- torch_rand(32, 128, 128, num_channels, names=c('N', 'H', 'W', 'C'))
more_imgs = torch_rand(32, num_channels, 128, 128, names=c('N', 'C', 'H', 'W'))
videos = torch_randn(3, num_channels, 128, 128, 128, names=c('N', 'C', 'H', 'W', 'D'))
# scale_channels is agnostic to the dimension order of the input
scale_channels(imgs, scale)
scale_channels(more_imgs, scale)
scale_channels(videos, scale)align_to
Permutes the dimensions of the self tensor to match the
order specified in names, adding size-one dims for any new
names.
All of the dims of self must be named in order to use
this method. The resulting tensor is a view on the original tensor.
All dimension names of self must be present in
names. names may contain additional names that
are not in self$names; the output tensor has a size-one
dimension for each of those new names.
all
all() -> bool
Returns TRUE if all elements in the tensor are TRUE, FALSE otherwise.
Examples:
a <- torch_rand(1, 2)$to(dtype = torch_bool())
a
a$all()all(dim, keepdim=FALSE, out=NULL) -> Tensor
Returns TRUE if all elements in each row of the tensor in the given
dimension dim are TRUE, FALSE otherwise.
If keepdim is TRUE, the output tensor is of
the same size as input except in the dimension
dim where it is of size 1. Otherwise, dim is
squeezed (see ?torch_squeeze()), resulting in the output
tensor having 1 fewer dimension than input.
Arguments:
- dim (int): the dimension to reduce
- keepdim (bool): whether the output tensor has
dimretained or not - out (Tensor, optional): the output tensor
Examples:
a <- torch_rand(4, 2)$to(dtype = torch_bool())
a
a$all(dim=2)
a$all(dim=1)any
any() -> bool
Returns TRUE if any elements in the tensor are TRUE, FALSE otherwise.
Examples:
a <- torch_rand(1, 2)$to(dtype = torch_bool())
a
a$any()any(dim, keepdim=FALSE, out=NULL) -> Tensor
Returns TRUE if any elements in each row of the tensor in the given
dimension dim are TRUE, FALSE otherwise.
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.
Arguments:
- dim (int): the dimension to reduce
- keepdim (bool): whether the output tensor has
dimretained or not - out (Tensor, optional): the output tensor
Examples:
a <- torch_randn(4, 2) < 0
a
a$any(2)
a$any(1)apply_
apply_(callable) -> Tensor
Applies the function callable to each element in the
tensor, replacing each element with the value returned by
callable.
as_subclass
as_subclass(cls) -> Tensor
Makes a cls instance with the same data pointer as
self. Changes in the output mirror changes in
self, and the output stays attached to the autograd graph.
cls must be a subclass of Tensor.
backward
Computes the gradient of current tensor w.r.t. graph leaves.
The graph is differentiated using the chain rule. If the tensor is
non-scalar (i.e. its data has more than one element) and requires
gradient, the function additionally requires specifying
gradient. It should be a tensor of matching type and
location, that contains the gradient of the differentiated function
w.r.t. self.
This function accumulates gradients in the leaves - you might need to
zero $grad attributes or set them to NULL
before calling it. See
Default gradient layouts<default-grad-layouts> for
details on the memory layout of accumulated gradients.
Arguments:
- gradient (Tensor or NULL): Gradient w.r.t. the tensor. If it is a
tensor, it will be automatically converted to a Tensor that does not
require grad unless
create_graphis TRUE. NULL values can be specified for scalar Tensors or ones that don’t require grad. If a NULL value would be acceptable then this argument is optional. - retain_graph (bool, optional): If
FALSE, the graph used to compute the grads will be freed. Note that in nearly all cases setting this option to TRUE is not needed and often can be worked around in a much more efficient way. Defaults to the value ofcreate_graph. - create_graph (bool, optional): If
TRUE, graph of the derivative will be constructed, allowing to compute higher order derivative products. Defaults toFALSE.
bernoulli
bernoulli(*, generator=NULL) -> Tensor
Returns a result tensor where each self must have floating point dtype, and the
result will have the same dtype.
See ?torch_bernoulli
bernoulli_
bernoulli_(p=0.5, *, generator=NULL) -> Tensor
Fills each location of self with an independent sample
from self can have integral dtype.
bernoulli_(p_tensor, *, generator=NULL) -> Tensor
p_tensor should be a tensor containing probabilities to
be used for drawing the binary random number.
The self tensor will be set to a value sampled from
self can have integral dtype, but
p_tensor must have floating point dtype.
See also $bernoulli and
?torch_bernoulli
bfloat16
bfloat16(memory_format=torch_preserve_format) -> Tensor
self$bfloat16() is equivalent to
self$to(torch_bfloat16). See [to()].
bool
bool(memory_format=torch_preserve_format) -> Tensor
self$bool() is equivalent to
self$to(torch_bool). See [to()].
byte
byte(memory_format=torch_preserve_format) -> Tensor
self$byte() is equivalent to
self$to(torch_uint8). See [to()].
cauchy_
cauchy_(median=0, sigma=1, *, generator=NULL) -> Tensor
Fills the tensor with numbers drawn from the Cauchy distribution:
char
char(memory_format=torch_preserve_format) -> Tensor
self$char() is equivalent to
self$to(torch_int8). See [to()].
clone
clone(memory_format=torch_preserve_format()) -> Tensor
Returns a copy of the self tensor. The copy has the same
size and data type as self.
x <- torch_tensor(1)
y <- x$clone()
x$add_(1)
ycontiguous
contiguous(memory_format=torch_contiguous_format) -> Tensor
Returns a contiguous in memory tensor containing the same data as
self tensor. If self tensor is already in the
specified memory format, this function returns the self
tensor.
copy_
copy_(src, non_blocking=FALSE) -> Tensor
Copies the elements from src into self
tensor and returns self.
The src tensor must be broadcastable with the
self tensor. It may be of a different data type or reside
on a different device.
cpu
cpu(memory_format=torch_preserve_format) -> Tensor
Returns a copy of this object in CPU memory.
If this object is already in CPU memory and on the correct device, then no copy is performed and the original object is returned.
cuda
cuda(device=NULL, non_blocking=FALSE, memory_format=torch_preserve_format) -> Tensor
Returns a copy of this object in CUDA memory.
If this object is already in CUDA memory and on the correct device, then no copy is performed and the original object is returned.
Arguments:
- device (
torch_device): The destination GPU device. Defaults to the current CUDA device. - non_blocking (bool): If
TRUEand the source is in pinned memory, the copy will be asynchronous with respect to the host. Otherwise, the argument has no effect. Default:FALSE. - memory_format (
torch_memory_format, optional): the desired memory format of - returned Tensor. Default:
torch_preserve_format.
dense_dim
dense_dim() -> int
If self is a sparse COO tensor (i.e., with
torch_sparse_coo layout), this returns the number of dense
dimensions. Otherwise, this throws an error.
See also $sparse_dim.
dequantize
dequantize() -> Tensor
Given a quantized Tensor, dequantize it and return the dequantized float Tensor.
detach
Returns a new Tensor, detached from the current graph.
The result will never require gradient.
Note:
Returned Tensor shares the same storage with the original one.
In-place modifications on either of them will be seen, and may trigger errors in correctness checks.
IMPORTANT NOTE: Previously, in-place size / stride /
storage changes (such as resize_ / resize_as_
/ set_ / transpose_) to the returned tensor
also update the original tensor. Now, these in-place changes will not
update the original tensor anymore, and will instead trigger an
error.
For sparse tensors: In-place indices / values changes (such as
zero_ / copy_ / add_) to the
returned tensor will not update the original tensor anymore, and will
instead trigger an error.
detach_
Detaches the Tensor from the graph that created it, making it a leaf. Views cannot be detached in-place.
double
double(memory_format=torch_preserve_format) -> Tensor
self$double() is equivalent to
self$to(torch_float64). See [to()].
element_size
element_size() -> int
Returns the size in bytes of an individual element.
Examples:
torch_tensor(c(1))$element_size()expand
expand(*sizes) -> Tensor
Returns a new view of the self tensor with singleton
dimensions expanded to a larger size.
Passing -1 as the size for a dimension means not changing the size of that dimension.
Tensor can be also expanded to a larger number of dimensions, and the new ones will be appended at the front. For the new dimensions, the size cannot be set to -1.
Expanding a tensor does not allocate new memory, but only creates a
new view on the existing tensor where a dimension of size one is
expanded to a larger size by setting the stride to 0. Any
dimension of size 1 can be expanded to an arbitrary value without
allocating new memory.
Warning:
More than one element of an expanded tensor may refer to a single memory location. As a result, in-place operations (especially ones that are vectorized) may result in incorrect behavior. If you need to write to the tensors, please clone them first.
Examples:
x <- torch_tensor(matrix(c(1,2,3), ncol = 1))
x$size()
x$expand(c(3, 4))
x$expand(c(-1, 4)) # -1 means not changing the size of that dimensionexpand_as
expand_as(other) -> Tensor
Expand this tensor to the same size as other.
self$expand_as(other) is equivalent to
self$expand(other.size()).
Please see $expand for more information about
expand.
exponential_
exponential_(lambd=1, *, generator=NULL) -> Tensor
Fills self tensor with elements drawn from the
exponential distribution:
fill_diagonal_
fill_diagonal_(fill_value, wrap=FALSE) -> Tensor
Fill the main diagonal of a tensor that has at least 2-dimensions. When dims>2, all dimensions of input must be of equal length. This function modifies the input tensor in-place, and returns the input tensor.
Arguments:
- fill_value (Scalar): the fill value
- wrap (bool): the diagonal ‘wrapped’ after N columns for tall matrices.
Examples:
a <- torch_zeros(3, 3)
a$fill_diagonal_(5)
b <- torch_zeros(7, 3)
b$fill_diagonal_(5)
c <- torch_zeros(7, 3)
c$fill_diagonal_(5, wrap=TRUE)float
float(memory_format=torch_preserve_format) -> Tensor
self$float() is equivalent to
self$to(torch_float32). See [to()].
geometric_
geometric_(p, *, generator=NULL) -> Tensor
Fills self tensor with elements drawn from the geometric
distribution:
get_device
get_device() -> Device ordinal (Integer)
For CUDA tensors, this function returns the device ordinal of the GPU on which the tensor resides. For CPU tensors, an error is thrown.
Examples:
x <- torch_randn(3, 4, 5, device='cuda:0')
x$get_device()
x$cpu()$get_device() # RuntimeError: get_device is not implemented for type torch_FloatTensorgrad
This attribute is NULL by default and becomes a Tensor
the first time a call to backward computes gradients for
self. The attribute will then contain the gradients
computed and future calls to [backward()] will accumulate (add)
gradients into it.
half
half(memory_format=torch_preserve_format) -> Tensor
self$half() is equivalent to
self$to(torch_float16). See [to()].
imag
Returns a new tensor containing imaginary values of the
self tensor. The returned tensor and self
share the same underlying storage.
Examples:
x <- torch_randn(4, dtype=torch_cfloat())
x
x$imagindex_add
index_add(tensor1, dim, index, tensor2) -> Tensor
Out-of-place version of $index_add_.
tensor1 corresponds to self in
$index_add_.
index_add_
index_add_(dim, index, tensor) -> Tensor
Accumulate the elements of tensor into the
self tensor by adding to the indices in the order given in
index. For example, if dim == 0 and
index[i] == j, then the i th row of
tensor is added to the j th row of
self.
The dim th dimension of tensor must have
the same size as the length of index (which must be a
vector), and all other dimensions must match self, or an
error will be raised.
Note:
In some circumstances when using the CUDA backend with CuDNN, this
operator may select a nondeterministic algorithm to increase
performance. If this is undesirable, you can try to make the operation
deterministic (potentially at a performance cost) by setting
torch_backends.cudnn.deterministic = TRUE.
Arguments:
- dim (int): dimension along which to index
- index (LongTensor): indices of
tensorto select from - tensor (Tensor): the tensor containing values to add
Examples:
x <- torch_ones(5, 3)
t <- torch_tensor(matrix(1:9, ncol = 3), dtype=torch_float())
index <- torch_tensor(c(1L, 4L, 3L))
x$index_add_(1, index, t)index_copy
index_copy(tensor1, dim, index, tensor2) -> Tensor
Out-of-place version of $index_copy_.
tensor1 corresponds to self in
$index_copy_.
index_copy_
index_copy_(dim, index, tensor) -> Tensor
Copies the elements of tensor into the self
tensor by selecting the indices in the order given in
index. For example, if dim == 0 and
index[i] == j, then the i th row of
tensor is copied to the j th row of
self.
The dim th dimension of tensor must have
the same size as the length of index (which must be a
vector), and all other dimensions must match self, or an
error will be raised.
Arguments:
- dim (int): dimension along which to index
- index (LongTensor): indices of
tensorto select from - tensor (Tensor): the tensor containing values to copy
Examples:
x <- torch_zeros(5, 3)
t <- torch_tensor(matrix(1:9, ncol = 3), dtype=torch_float())
index <- torch_tensor(c(1, 5, 3))
x$index_copy_(1, index, t)index_fill
index_fill(tensor1, dim, index, value) -> Tensor
Out-of-place version of $index_fill_.
tensor1 corresponds to self in
$index_fill_.
index_fill_
index_fill_(dim, index, val) -> Tensor
Fills the elements of the self tensor with value
val by selecting the indices in the order given in
index.
Arguments:
- dim (int): dimension along which to index
- index (LongTensor): indices of
selftensor to fill in - val (float): the value to fill with
Examples:
x <- torch_tensor(matrix(1:9, ncol = 3), dtype=torch_float())
index <- torch_tensor(c(1, 3), dtype = torch_long())
x$index_fill_(1, index, -1)index_put
index_put(tensor1, indices, value, accumulate=FALSE) -> Tensor
Out-place version of $index_put_. tensor1
corresponds to self in $index_put_.
index_put_
index_put_(indices, value, accumulate=FALSE) -> Tensor
Puts values from the tensor value into the tensor
self using the indices specified in indices
(which is a tuple of Tensors). The expression
tensor.index_put_(indices, value) is equivalent to
tensor[indices] = value. Returns self.
If accumulate is TRUE, the elements in
value are added to self. If accumulate is
FALSE, the behavior is undefined if indices contain
duplicate elements.
indices
indices() -> Tensor
If self is a sparse COO tensor (i.e., with
torch_sparse_coo layout), this returns a view of the
contained indices tensor. Otherwise, this throws an error.
See also Tensor.values.
int
int(memory_format=torch_preserve_format) -> Tensor
self$int() is equivalent to
self$to(torch_int32). See [to()].
int_repr
int_repr() -> Tensor
Given a quantized Tensor, self$int_repr() returns a CPU
Tensor with uint8_t as data type that stores the underlying uint8_t
values of the given Tensor.
irfft
irfft(signal_ndim, normalized=FALSE, onesided=TRUE, signal_sizes=NULL) -> Tensor
See ?torch_irfft
is_contiguous
is_contiguous(memory_format=torch_contiguous_format) -> bool
Returns TRUE if self tensor is contiguous in memory in
the order specified by memory format.
is_floating_point
is_floating_point() -> bool
Returns TRUE if the data type of self is a floating
point data type.
is_leaf
All Tensors that have requires_grad which is
FALSE will be leaf Tensors by convention.
For Tensors that have requires_grad which is
TRUE, they will be leaf Tensors if they were created by the
user. This means that they are not the result of an operation and so
grad_fn is NULL.
Only leaf Tensors will have their grad populated during
a call to [backward()]. To get grad populated for non-leaf
Tensors, you can use [retain_grad()].
Examples:
a <- torch_rand(10, requires_grad=TRUE)
a$is_leaf
# b <- torch_rand(10, requires_grad=TRUE)$cuda()
# b$is_leaf()
# FALSE
# b was created by the operation that cast a cpu Tensor into a cuda Tensor
c <- torch_rand(10, requires_grad=TRUE) + 2
c$is_leaf
# c was created by the addition operation
# d <- torch_rand(10)$cuda()
# d$is_leaf()
# TRUE
# d does not require gradients and so has no operation creating it (that is tracked by the autograd engine)
# e <- torch_rand(10)$cuda()$requires_grad_()
# e$is_leaf()
# TRUE
# e requires gradients and has no operations creating it
# f <- torch_rand(10, requires_grad=TRUE, device="cuda")
# f$is_leaf
# TRUE
# f requires grad, has no operation creating itis_meta
Is TRUE if the Tensor is a meta tensor,
FALSE otherwise. Meta tensors are like normal tensors, but
they carry no data.
is_set_to
is_set_to(tensor) -> bool
Returns TRUE if this object refers to the same THTensor
object from the Torch C API as the given tensor.
istft
See ?torch_istft ## item
item() -> number
Returns the value of this tensor as a standard Python number. This
only works for tensors with one element. For other cases, see
$tolist.
This operation is not differentiable.
Examples:
x <- torch_tensor(1.0)
x$item()log_normal_
log_normal_(mean=1, std=2, *, generator=NULL)
Fills self tensor with numbers samples from the
log-normal distribution parameterized by the given mean \mu
and standard deviation \sigma. Note that mean
and std are the mean and standard deviation of the
underlying normal distribution, and not of the returned
distribution:
long
long(memory_format=torch_preserve_format) -> Tensor
self$long() is equivalent to
self$to(torch_int64). See [to()].
map_
map_(tensor, callable)
Applies callable for each element in self
tensor and the given tensor and stores the results in
self tensor. self tensor and the given
tensor must be broadcastable.
The callable should have the signature:
callable(a, b) -> number
masked_fill_
masked_fill_(mask, value)
Fills elements of self tensor with value
where mask is TRUE. The shape of mask must be
broadcastable <broadcasting-semantics> with the shape
of the underlying tensor.
masked_scatter_
masked_scatter_(mask, source)
Copies elements from source into self
tensor at positions where the mask is TRUE. The shape of
mask must be
:ref:broadcastable <broadcasting-semantics> with the
shape of the underlying tensor. The source should have at
least as many elements as the number of ones in mask
names
Stores names for each of this tensor’s dimensions.
names[idx] corresponds to the name of tensor dimension
idx. Names are either a string if the dimension is named or
NULL if the dimension is unnamed.
Dimension names may contain characters or underscore. Furthermore, a dimension name must be a valid Python variable name (i.e., does not start with underscore).
Tensors may not have two named dimensions with the same name.
narrow
narrow(dimension, start, length) -> Tensor
See ?torch_narrow
Examples:
x <- torch_tensor(matrix(1:9, ncol = 3))
x$narrow(1, 1, 3)
x$narrow(1, 1, 2)narrow_copy
narrow_copy(dimension, start, length) -> Tensor
Same as Tensor.narrow except returning a copy rather
than shared storage. This is primarily for sparse tensors, which do not
have a shared-storage narrow method. Calling
narrow_copy` withdimemsion > self
new_empty
new_empty(size, dtype=NULL, device=NULL, requires_grad=FALSE) -> Tensor
Returns a Tensor of size size filled with uninitialized
data. By default, the returned Tensor has the same
torch_dtype and torch_device as this
tensor.
Arguments:
- dtype (
torch_dtype, optional): the desired type of returned tensor. Default: if NULL, sametorch_dtypeas this tensor. - device (
torch_device, optional): the desired device of returned tensor. Default: if NULL, sametorch_deviceas this tensor. - requires_grad (bool, optional): If autograd should record operations on the
- returned tensor. Default:
FALSE.
Examples:
tensor <- torch_ones(5)
tensor$new_empty(c(2, 3))new_full
new_full(size, fill_value, dtype=NULL, device=NULL, requires_grad=FALSE) -> Tensor
Returns a Tensor of size size filled with
fill_value. By default, the returned Tensor has the same
torch_dtype and torch_device as this
tensor.
Arguments:
- fill_value (scalar): the number to fill the output tensor with.
- dtype (
torch_dtype, optional): the desired type of returned tensor. Default: if NULL, sametorch_dtypeas this tensor. - device (
torch_device, optional): the desired device of returned tensor. Default: if NULL, sametorch_deviceas this tensor. - requires_grad (bool, optional): If autograd should record operations on the
- returned tensor. Default:
FALSE.
Examples:
tensor <- torch_ones(c(2), dtype=torch_float64())
tensor$new_full(c(3, 4), 3.141592)new_ones
new_ones(size, dtype=NULL, device=NULL, requires_grad=FALSE) -> Tensor
Returns a Tensor of size size filled with
1. By default, the returned Tensor has the same
torch_dtype and torch_device as this
tensor.
Arguments:
- size (int…): a list, tuple, or
torch_Sizeof integers defining the - shape of the output tensor.
- dtype (
torch_dtype, optional): the desired type of returned tensor. Default: if NULL, sametorch_dtypeas this tensor. - device (
torch_device, optional): the desired device of returned tensor. Default: if NULL, sametorch_deviceas this tensor. - requires_grad (bool, optional): If autograd should record operations on the
- returned tensor. Default:
FALSE.
Examples:
tensor <- torch_tensor(c(2), dtype=torch_int32())
tensor$new_ones(c(2, 3))new_tensor
new_tensor(data, dtype=NULL, device=NULL, requires_grad=FALSE) -> Tensor
Returns a new Tensor with data as the tensor data. By
default, the returned Tensor has the same torch_dtype and
torch_device as this tensor.
Warning:
new_tensor always copies
data(). If you have a Tensordata` and want to avoid a copy,
use [
When data is a tensor x, [new_tensor()()] reads out ‘the
data’ from whatever it is passed, and constructs a leaf variable.
Therefore tensor$new_tensor(x) is equivalent to
x$clone()$detach() and
tensor$new_tensor(x, requires_grad=TRUE) is equivalent to
x$clone()$detach()$requires_grad_(TRUE). The equivalents
using clone() and detach() are
recommended.
Arguments:
- data (array_like): The returned Tensor copies
data. - dtype (
torch_dtype, optional): the desired type of returned tensor. Default: if NULL, sametorch_dtypeas this tensor. - device (
torch_device, optional): the desired device of returned tensor. Default: if NULL, sametorch_deviceas this tensor. - requires_grad (bool, optional): If autograd should record operations on the
- returned tensor. Default:
FALSE.
Examples:
tensor <- torch_ones(c(2), dtype=torch_int8)
data <- matrix(1:4, ncol = 2)
tensor$new_tensor(data)new_zeros
new_zeros(size, dtype=NULL, device=NULL, requires_grad=FALSE) -> Tensor
Returns a Tensor of size size filled with
0. By default, the returned Tensor has the same
torch_dtype and torch_device as this
tensor.
Arguments:
- size (int…): a list, tuple, or
torch_Sizeof integers defining the - shape of the output tensor.
- dtype (
torch_dtype, optional): the desired type of returned tensor. Default: if NULL, sametorch_dtypeas this tensor. - device (
torch_device, optional): the desired device of returned tensor. Default: if NULL, sametorch_deviceas this tensor. - requires_grad (bool, optional): If autograd should record operations on the
- returned tensor. Default:
FALSE.
Examples:
tensor <- torch_tensor(c(1), dtype=torch_float64())
tensor$new_zeros(c(2, 3))norm
See ?torch_norm ## normal_
normal_(mean=0, std=1, *, generator=NULL) -> Tensor
Fills self tensor with elements samples from the normal
distribution parameterized by mean and
std.
numpy
numpy() -> numpy.ndarray
Returns self tensor as a NumPy
:class:ndarray. This tensor and the returned
ndarray share the same underlying storage. Changes to
self tensor will be reflected in the
:class:ndarray and vice versa.
permute
permute(*dims) -> Tensor
Returns a view of the original tensor with its dimensions permuted.
Examples:
x <- torch_randn(2, 3, 5)
x$size()
x$permute(c(3, 1, 2))$size()put_
put_(indices, tensor, accumulate=FALSE) -> Tensor
Copies the elements from tensor into the positions
specified by indices. For the purpose of indexing, the self
tensor is treated as if it were a 1-D tensor.
If accumulate is TRUE, the elements in
tensor are added to self. If accumulate is
FALSE, the behavior is undefined if indices contain
duplicate elements.
Arguments:
- indices (LongTensor): the indices into self
- tensor (Tensor): the tensor containing values to copy from
- accumulate (bool): whether to accumulate into self
Examples:
src <- torch_tensor(matrix(3:8, ncol = 3))
src$put_(torch_tensor(1:2), torch_tensor(9:10))q_per_channel_axis
q_per_channel_axis() -> int
Given a Tensor quantized by linear (affine) per-channel quantization, returns the index of dimension on which per-channel quantization is applied.
q_per_channel_scales
q_per_channel_scales() -> Tensor
Given a Tensor quantized by linear (affine) per-channel quantization, returns a Tensor of scales of the underlying quantizer. It has the number of elements that matches the corresponding dimensions (from q_per_channel_axis) of the tensor.
q_per_channel_zero_points
q_per_channel_zero_points() -> Tensor
Given a Tensor quantized by linear (affine) per-channel quantization, returns a tensor of zero_points of the underlying quantizer. It has the number of elements that matches the corresponding dimensions (from q_per_channel_axis) of the tensor.
q_scale
q_scale() -> float
Given a Tensor quantized by linear(affine) quantization, returns the scale of the underlying quantizer().
q_zero_point
q_zero_point() -> int
Given a Tensor quantized by linear(affine) quantization, returns the zero_point of the underlying quantizer().
random_
random_(from=0, to=NULL, *, generator=NULL) -> Tensor
Fills self tensor with numbers sampled from the discrete
uniform distribution over [from, to - 1]. If not specified,
the values are usually only bounded by self tensor’s data
type. However, for floating point types, if unspecified, range will be
[0, 2^mantissa] to ensure that every value is
representable. For example,
torch_tensor(1, dtype=torch_double).random_() will be
uniform in [0, 2^53].
real
Returns a new tensor containing real values of the self
tensor. The returned tensor and self share the same
underlying storage.
Examples:
x <- torch_randn(4, dtype=torch_cfloat())
x
x$realrecord_stream
record_stream(stream)
Ensures that the tensor memory is not reused for another tensor until
all current work queued on stream are complete.
Note:
The caching allocator is aware of only the stream where a tensor was allocated. Due to the awareness, it already correctly manages the life cycle of tensors on only one stream. But if a tensor is used on a stream different from the stream of origin, the allocator might reuse the memory unexpectedly. Calling this method lets the allocator know which streams have used the tensor.
refine_names
Refines the dimension names of self according to
names.
Refining is a special case of renaming that “lifts” unnamed
dimensions. A NULL dim can be refined to have any name; a
named dim can only be refined to have the same name.
Because named tensors can coexist with unnamed tensors, refining names gives a nice way to write named-tensor-aware code that works with both named and unnamed tensors.
names may contain up to one Ellipsis (...).
The Ellipsis is expanded greedily; it is expanded in-place to fill
names to the same length as self$dim() using
names from the corresponding indices of self$names.
Arguments:
- names (iterable of str): The desired names of the output tensor. May contain up to one Ellipsis.
Examples:
imgs <- torch_randn(32, 3, 128, 128)
named_imgs <- imgs$refine_names(c('N', 'C', 'H', 'W'))
named_imgs$namesregister_hook
Registers a backward hook.
The hook will be called every time a gradient with respect to the Tensor is computed. The hook should have the following signature::
hook(grad) -> Tensor or NULL
The hook should not modify its argument, but it can optionally return
a new gradient which will be used in place of grad.
This function returns a handle with a method
handle$remove() that removes the hook from the module.
Example
v <- torch_tensor(c(0., 0., 0.), requires_grad=TRUE)
h <- v$register_hook(function(grad) grad * 2) # double the gradient
v$backward(torch_tensor(c(1., 2., 3.)))
v$grad
h$remove()rename
Renames dimension names of self.
There are two main usages:
self$rename(**rename_map) returns a view on tensor that
has dims renamed as specified in the mapping
rename_map.
self$rename(*names) returns a view on tensor, renaming
all dimensions positionally using names. Use
self$rename(NULL) to drop names on a tensor.
One cannot specify both positional args names and
keyword args rename_map.
Examples:
imgs <- torch_rand(2, 3, 5, 7, names=c('N', 'C', 'H', 'W'))
renamed_imgs <- imgs$rename(c("Batch", "Channels", "Height", "Width"))repeat
repeat(*sizes) -> Tensor
Repeats this tensor along the specified dimensions.
Unlike $expand, this function copies the tensor’s
data.
Arguments:
- sizes (torch_Size or int…): The number of times to repeat this tensor along each
- dimension
Examples:
x <- torch_tensor(c(1, 2, 3))
x$`repeat`(c(4, 2))
x$`repeat`(c(4, 2, 1))$size()requires_grad_
requires_grad_(requires_grad=TRUE) -> Tensor
Change if autograd should record operations on this tensor: sets this
tensor’s requires_grad attribute in-place. Returns this
tensor.
[requires_grad_()]’s main use case is to tell autograd to begin
recording operations on a Tensor tensor. If
tensor has requires_grad=FALSE (because it was
obtained through a DataLoader, or required preprocessing or
initialization), tensor.requires_grad_() makes it so that
autograd will begin to record operations on tensor.
Arguments:
- requires_grad (bool): If autograd should record operations on this
tensor. Default:
TRUE.
Examples:
# Let's say we want to preprocess some saved weights and use
# the result as new weights.
saved_weights <- c(0.1, 0.2, 0.3, 0.25)
loaded_weights <- torch_tensor(saved_weights)
weights <- preprocess(loaded_weights) # some function
weights
# Now, start to record operations done to weights
weights$requires_grad_()
out <- weights$pow(2)$sum()
out$backward()
weights$gradreshape
reshape(*shape) -> Tensor
Returns a tensor with the same data and number of elements as
self but with the specified shape. This method returns a
view if shape is compatible with the current shape. See
$view on when it is possible to return a view.
See ?torch_reshape
reshape_as
reshape_as(other) -> Tensor
Returns this tensor as the same shape as other.
self$reshape_as(other) is equivalent to
self$reshape(other.sizes()). This method returns a view if
other.sizes() is compatible with the current shape. See
$view on when it is possible to return a view.
Please see reshape for more information about
reshape.
resize_
resize_(*sizes, memory_format=torch_contiguous_format) -> Tensor
Resizes self tensor to the specified size. If the number
of elements is larger than the current storage size, then the underlying
storage is resized to fit the new number of elements. If the number of
elements is smaller, the underlying storage is not changed. Existing
elements are preserved but any new memory is uninitialized.
Warning:
This is a low-level method. The storage is reinterpreted as
C-contiguous, ignoring the current strides (unless the target size
equals the current size, in which case the tensor is left unchanged).
For most purposes, you will instead want to use $view(),
which checks for contiguity, or $reshape(), which copies
data if needed. To change the size in-place with custom strides, see
$set_().
Arguments:
- sizes (torch_Size or int…): the desired size
- memory_format (
torch_memory_format, optional): the desired memory format of Tensor. Default:torch_contiguous_format. Note that memory format ofselfis going to be unaffected ifself$size()matchessizes.
Examples:
x <- torch_tensor(matrix(1:6, ncol = 2))
x$resize_(c(2, 2))resize_as_
resize_as_(tensor, memory_format=torch_contiguous_format) -> Tensor
Resizes the self tensor to be the same size as the
specified tensor. This is equivalent to
self$resize_(tensor.size()).
scatter_
scatter_(dim, index, src) -> Tensor
Writes all values from the tensor src into
self at the indices specified in the index
tensor. For each value in src, its output index is
specified by its index in src for
dimension != dim and by the corresponding value in
index for dimension = dim.
For a 3-D tensor, self is updated as:
self[index[i][j][k]][j][k] = src[i][j][k] # if dim == 0
self[i][index[i][j][k]][k] = src[i][j][k] # if dim == 1
self[i][j][index[i][j][k]] = src[i][j][k] # if dim == 2This is the reverse operation of the manner described in
$gather.
self, index and src (if it is
a Tensor) should have same number of dimensions. It is also required
that index.size(d) <= src.size(d) for all dimensions
d, and that index.size(d) <= self$size(d)
for all dimensions d != dim.
Moreover, as for $gather, the values of
index must be between 0 and
self$size(dim) - 1 inclusive, and all values in a row along
the specified dimension dim must be unique.
Arguments:
- dim (int): the axis along which to index
- index (LongTensor): the indices of elements to scatter,
- can be either empty or the same size of src. When empty, the operation returns identity
- src (Tensor): the source element(s) to scatter,
- incase
valueis not specified - value (float): the source element(s) to scatter,
- incase
srcis not specified
Examples:
x <- torch_rand(2, 5)
x
torch_zeros(3, 5)$scatter_(
1,
torch_tensor(rbind(c(2, 3, 3, 1, 1), c(3, 1, 1, 2, 3)), x)
)
z <- torch_zeros(2, 4)$scatter_(
2,
torch_tensor(matrix(3:4, ncol = 1)), 1.23
)scatter_add_
scatter_add_(dim, index, src) -> Tensor
Adds all values from the tensor other into
self at the indices specified in the index
tensor in a similar fashion as ~$scatter_. For each value
in src, it is added to an index in self which
is specified by its index in src for
dimension != dim and by the corresponding value in
index for dimension = dim.
For a 3-D tensor, self is updated as::
self[index[i][j][k]][j][k] += src[i][j][k] # if dim == 0
self[i][index[i][j][k]][k] += src[i][j][k] # if dim == 1
self[i][j][index[i][j][k]] += src[i][j][k] # if dim == 2self, index and src should
have same number of dimensions. It is also required that
index.size(d) <= src.size(d) for all dimensions
d, and that index.size(d) <= self$size(d)
for all dimensions d != dim.
Note:
In some circumstances when using the CUDA backend with CuDNN, this
operator may select a nondeterministic algorithm to increase
performance. If this is undesirable, you can try to make the operation
deterministic (potentially at a performance cost) by setting
torch_backends.cudnn.deterministic = TRUE.
Arguments:
- dim (int): the axis along which to index
- index (LongTensor): the indices of elements to scatter and add,
- can be either empty or the same size of src. When empty, the operation returns identity.
- src (Tensor): the source elements to scatter and add
Examples:
x <- torch_rand(2, 5)
x
torch_ones(3, 5)$scatter_add_(1, torch_tensor(rbind(c(0, 1, 2, 0, 0), c(2, 0, 0, 1, 2))), x)select
select(dim, index) -> Tensor
Slices the self tensor along the selected dimension at
the given index. This function returns a view of the original tensor
with the given dimension removed.
set_
set_(source=NULL, storage_offset=0, size=NULL, stride=NULL) -> Tensor
Sets the underlying storage, size, and strides. If
source is a tensor, self tensor will share the
same storage and have the same size and strides as source.
Changes to elements in one tensor will be reflected in the other.
share_memory_
Moves the underlying storage to shared memory.
This is a no-op if the underlying storage is already in shared memory and for CUDA tensors. Tensors in shared memory cannot be resized.
short
short(memory_format=torch_preserve_format) -> Tensor
self$short() is equivalent to
self$to(torch_int16). See [to()].
size
size() -> torch_Size
Returns the size of the self tensor. The returned value
is a subclass of tuple.
Examples:
torch_empty(3, 4, 5)$size()sparse_dim
sparse_dim() -> int
If self is a sparse COO tensor (i.e., with
torch_sparse_coo layout), this returns the number of sparse
dimensions. Otherwise, this throws an error.
See also Tensor.dense_dim.
sparse_mask
sparse_mask(input, mask) -> Tensor
Returns a new SparseTensor with values from Tensor input
filtered by indices of mask and values are ignored.
input and mask must have the same shape.
split
See ?torch_split
stft
See ?torch_stft
storage_offset
storage_offset() -> int
Returns self tensor’s offset in the underlying storage
in terms of number of storage elements (not bytes).
Examples:
x <- torch_tensor(c(1, 2, 3, 4, 5))
x$storage_offset()
x[3:N]$storage_offset()stride
stride(dim) -> tuple or int
Returns the stride of self tensor.
Stride is the jump necessary to go from one element to the next one
in the specified dimension dim. A tuple of all strides is
returned when no argument is passed in. Otherwise, an integer value is
returned as the stride in the particular dimension dim.
Examples:
x <- torch_tensor(matrix(1:10, nrow = 2))
x$stride()
x$stride(1)
x$stride(-1)sub
sub(other, *, alpha=1) -> Tensor
Subtracts a scalar or tensor from self tensor. If both
alpha and other are specified, each element of
other is scaled by alpha before being
used.
When other is a tensor, the shape of other
must be broadcastable <broadcasting-semantics> with
the shape of the underlying tensor.
sum_to_size
sum_to_size(*size) -> Tensor
Sum this tensor to size. size
must be broadcastable to this tensor size.
to
to(*args, **kwargs) -> Tensor
Performs Tensor dtype and/or device conversion. A
torch_dtype and :class:torch_device are
inferred from the arguments of
self$to(*args, **kwargs).
Note:
If the self Tensor already has the correct
torch_dtype and :class:torch_device, then
self is returned. Otherwise, the returned tensor is a copy
of self with the desired torch_dtype and
:class:torch_device.
Here are the ways to call to:
to(dtype, non_blocking=FALSE, copy=FALSE, memory_format=torch_preserve_format) -> Tensor
Returns a Tensor with the specified dtype
Arguments:
- memory_format (
torch_memory_format, optional): the desired memory format of returned Tensor. Default:torch_preserve_format.
to(device=NULL, dtype=NULL, non_blocking=FALSE, copy=FALSE, memory_format=torch_preserve_format) -> Tensor
Returns a Tensor with the specified device and
(optional) dtype. If dtype is
NULL it is inferred to be self$dtype. When
non_blocking, tries to convert asynchronously with respect
to the host if possible, e.g., converting a CPU Tensor with pinned
memory to a CUDA Tensor.
When copy is set, a new Tensor is created even when the
Tensor already matches the desired conversion.
Arguments:
- memory_format (
torch_memory_format, optional): the desired memory format of returned Tensor. Default:torch_preserve_format.
function:: to(other, non_blocking=FALSE, copy=FALSE) -> Tensor
Returns a Tensor with same torch_dtype and
:class:torch_device as the Tensor other. When
non_blocking, tries to convert asynchronously with respect
to the host if possible, e.g., converting a CPU Tensor with pinned
memory to a CUDA Tensor.
When copy is set, a new Tensor is created even when the
Tensor already matches the desired conversion.
Examples:
tensor <- torch_randn(2, 2) # Initially dtype=float32, device=cpu
tensor$to(dtype = torch_float64())
other <- torch_randn(1, dtype=torch_float64())
tensor$to(other = other, non_blocking=TRUE)to_sparse
to_sparse(sparseDims) -> Tensor Returns a sparse copy of the
tensor. PyTorch supports sparse tensors in
coordinate format <sparse-docs>.
tolist
tolist() -> list or number
Returns the tensor as a (nested) list. For scalars, a standard Python
number is returned, just like with $item. Tensors are
automatically moved to the CPU first if necessary.
This operation is not differentiable.
triangular_solve
triangular_solve(A, upper=TRUE, transpose=FALSE, unitriangular=FALSE) -> (Tensor, Tensor)
See [torch_triangular_solve()]
type
type(dtype=NULL, non_blocking=FALSE, **kwargs) -> str or Tensor
Returns the type if dtype is not provided, else casts this
object to the specified type.
If this is already of the correct type, no copy is performed and the original object is returned.
Arguments:
- dtype (type or string): The desired type
- non_blocking (bool): If
TRUE, and the source is in pinned memory - and destination is on the GPU or vice versa, the copy is performed
- asynchronously with respect to the host. Otherwise, the argument
- has no effect. **kwargs: For compatibility, may contain the key
asyncin place of - the
non_blockingargument. Theasyncarg is deprecated.
type_as
type_as(tensor) -> Tensor
Returns this tensor cast to the type of the given tensor.
This is a no-op if the tensor is already of the correct type. This is
equivalent to self$type(tensor.type())
unfold
unfold(dimension, size, step) -> Tensor
Returns a view of the original tensor which contains all slices of
size size from self tensor in the dimension
dimension.
Step between two slices is given by step.
If sizedim is the size of dimension
dimension for self, the size of dimension
dimension in the returned tensor will be
(sizedim - size) / step + 1.
An additional dimension of size size is appended in the
returned tensor.
uniform_
uniform_(from=0, to=1) -> Tensor
Fills self tensor with numbers sampled from the
continuous uniform distribution:
unique_consecutive
Eliminates all but the first element from every consecutive group of equivalent elements.
See [torch_unique_consecutive()]
values
values() -> Tensor
If self is a sparse COO tensor (i.e., with
torch_sparse_coo layout), this returns a view of the
contained values tensor. Otherwise, this throws an error.
view
view(*shape) -> Tensor
Returns a new tensor with the same data as the self
tensor but of a different shape.
The returned tensor shares the same data and must have the same
number of elements, but may have a different size. For a tensor to be
viewed, the new view size must be compatible with its original size and
stride, i.e., each new view dimension must either be a subspace of an
original dimension, or only span across original dimensions
d, d+1, \dots, d+k that satisfy the following
contiguity-like condition that
\forall i = d, \dots, d+k-1,
Otherwise, it will not be possible to view self tensor
as shape without copying it (e.g., via
contiguous). When it is unclear whether a view
can be performed, it is advisable to use :meth:reshape,
which returns a view if the shapes are compatible, and copies
(equivalent to calling contiguous) otherwise.
view_as
view_as(other) -> Tensor
View this tensor as the same size as other.
self$view_as(other) is equivalent to
self$view(other.size()).
Please see $view for more information about
view.
where
where(condition, y) -> Tensor
self$where(condition, y) is equivalent to
torch_where(condition, self, y). See
?torch_where