oneflow.nn.Conv3d¶
-
class
oneflow.nn.
Conv3d
(in_channels: int, out_channels: int, kernel_size: Union[int, Tuple[int, int, int]], stride: Union[int, Tuple[int, int, int]] = 1, padding: Union[str, int, Tuple[int, int, int]] = 0, dilation: Union[int, Tuple[int, int, int]] = 1, groups: int = 1, bias: bool = True, padding_mode: str = 'zeros', device=None, dtype=None)¶ Applies a 3D convolution over an input signal composed of several input planes.
The interface is consistent with PyTorch. The documentation is referenced from: https://pytorch.org/docs/1.10/generated/torch.nn.Conv3d.html.
In the simplest case, the output value of the layer with input size \((N, C_{in}, D, H, W)\) and output \((N, C_{out}, D_{out}, H_{out}, W_{out})\) can be precisely described as:
\[out(N_i, C_{out_j}) = bias(C_{out_j}) + \sum_{k = 0}^{C_{in} - 1} weight(C_{out_j}, k) \star input(N_i, k)\]where \(\star\) is the valid 3D cross-correlation operator
stride
controls the stride for the cross-correlation.padding
controls the amount of padding applied to the input. It can be either a string {{‘valid’, ‘same’}} or a tuple of ints giving the amount of implicit padding applied on both sides.dilation
controls the spacing between the kernel points; also known as the à trous algorithm. It is harder to describe, but this link has a nice visualization of whatdilation
does.
The parameters
kernel_size
,stride
,padding
,dilation
can either be:a single
int
– in which case the same value is used for the depth, height and width dimensiona
tuple
of three ints – in which case, the first int is used for the depth dimension, the second int for the height dimension and the third int for the width dimension
Note
padding='valid'
is the same as no padding.padding='same'
pads the input so the output has the shape as the input. However, this mode doesn’t support any stride values other than 1.- Parameters
in_channels (int) – Number of channels in the input image
out_channels (int) – Number of channels produced by the convolution
kernel_size (int or tuple) – Size of the convolving kernel
stride (int or tuple, optional) – Stride of the convolution. Default: 1
padding (int, tuple or str, optional) – Padding added to all six sides of the input. Default: 0
padding_mode (string, optional) –
'zeros'
. Default:'zeros'
dilation (int or tuple, optional) – Spacing between kernel elements. Default: 1
groups (int, optional) – Number of blocked connections from input channels to output channels. Default: 1
bias (bool, optional) – If
True
, adds a learnable bias to the output. Default:True
- Shape:
Input: \((N, C_{in}, D_{in}, H_{in}, W_{in})\)
Output: \((N, C_{out}, D_{out}, H_{out}, W_{out})\) where
\[D_{out} = \left\lfloor\frac{D_{in} + 2 \times \text{padding}[0] - \text{dilation}[0] \times (\text{kernel\_size}[0] - 1) - 1}{\text{stride}[0]} + 1\right\rfloor\]\[H_{out} = \left\lfloor\frac{H_{in} + 2 \times \text{padding}[1] - \text{dilation}[1] \times (\text{kernel\_size}[1] - 1) - 1}{\text{stride}[1]} + 1\right\rfloor\]\[W_{out} = \left\lfloor\frac{W_{in} + 2 \times \text{padding}[2] - \text{dilation}[2] \times (\text{kernel\_size}[2] - 1) - 1}{\text{stride}[2]} + 1\right\rfloor\]
-
weight
¶ the learnable weights of the module of shape \((\text{out\_channels}, \frac{\text{in\_channels}}{\text{groups}},\) \(\text{kernel\_size[0]}, \text{kernel\_size[1]}, \text{kernel\_size[2]})\). The values of these weights are sampled from \(\mathcal{U}(-\sqrt{k}, \sqrt{k})\) where \(k = \frac{groups}{C_\text{in} * \prod_{i=0}^{2}\text{kernel\_size}[i]}\)
- Type
-
bias
¶ the learnable bias of the module of shape (out_channels). If
bias
isTrue
, then the values of these weights are sampled from \(\mathcal{U}(-\sqrt{k}, \sqrt{k})\) where \(k = \frac{groups}{C_\text{in} * \prod_{i=0}^{2}\text{kernel\_size}[i]}\)- Type
For example:
>>> import numpy as np >>> import oneflow as flow >>> import oneflow.nn as nn >>> arr = np.random.randn(1, 2, 5, 5, 5) >>> input = flow.Tensor(arr) >>> m = nn.Conv3d(2, 4, kernel_size=3, stride=1) >>> output = m(input)