Applies a 1D max pooling over an input signal composed of several input planes.
Usage
nn_max_pool1d(
kernel_size,
stride = NULL,
padding = 0,
dilation = 1,
return_indices = FALSE,
ceil_mode = FALSE
)
Arguments
- kernel_size
the size of the window to take a max over
- stride
the stride of the window. Default value is
kernel_size
- padding
implicit zero padding to be added on both sides
- dilation
a parameter that controls the stride of elements in the window
- return_indices
if
TRUE
, will return the max indices along with the outputs. Useful fornn_max_unpool1d()
later.- ceil_mode
when
TRUE
, will useceil
instead offloor
to compute the output shape
Details
In the simplest case, the output value of the layer with input size \((N, C, L)\) and output \((N, C, L_{out})\) can be precisely described as:
$$ out(N_i, C_j, k) = \max_{m=0, \ldots, \mbox{kernel\_size} - 1} input(N_i, C_j, stride \times k + m) $$
If padding
is non-zero, then the input is implicitly zero-padded on both sides
for padding
number of points. dilation
controls the spacing between the kernel points.
It is harder to describe, but this link
has a nice visualization of what dilation
does.
Shape
Input: \((N, C, L_{in})\)
Output: \((N, C, L_{out})\), where
$$ L_{out} = \left\lfloor \frac{L_{in} + 2 \times \mbox{padding} - \mbox{dilation} \times (\mbox{kernel\_size} - 1) - 1}{\mbox{stride}} + 1\right\rfloor $$
Examples
if (torch_is_installed()) {
# pool of size=3, stride=2
m <- nn_max_pool1d(3, stride = 2)
input <- torch_randn(20, 16, 50)
output <- m(input)
}