--- /dev/null
+#!/usr/bin/env python
+
+import torch
+from torch import nn
+
+######################################################################
+
+def conv_chain(input_size, output_size, depth, cond):
+ if depth == 0:
+ if input_size == output_size:
+ return [ [ ] ]
+ else:
+ return [ ]
+ else:
+ r = [ ]
+ for kernel_size in range(1, input_size + 1):
+ for stride in range(1, input_size + 1):
+ if cond(kernel_size, stride):
+ n = (input_size - kernel_size) // stride
+ if n * stride + kernel_size == input_size:
+ q = conv_chain(n + 1, output_size, depth - 1, cond)
+ r += [ [ (kernel_size, stride) ] + u for u in q ]
+ return r
+
+######################################################################
+
+# Example
+
+c = conv_chain(
+ input_size = 64, output_size = 8,
+ depth = 5,
+ cond = lambda k, s: k <= 4 and s <= 2 and s <= k//2
+)
+
+x = torch.rand(1, 1, 64)
+
+for m in c:
+ m = nn.Sequential(*[ nn.Conv1d(1, 1, l[0], l[1]) for l in m ])
+ print(m)
+ print(x.size(), m(x).size())
+
+######################################################################