From 3b0d1e7d03469ed17d1eec931bd76c857b99ff3a Mon Sep 17 00:00:00 2001
From: Laurent Mazare <laurent.mazare@gmail.com>
Date: Fri, 3 Nov 2023 11:18:25 +0100
Subject: [PATCH] Transposed conv1d in candle-nn. (#1252)

---
 candle-nn/src/conv.rs | 94 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/candle-nn/src/conv.rs b/candle-nn/src/conv.rs
index 7c0bf841..b1168405 100644
--- a/candle-nn/src/conv.rs
+++ b/candle-nn/src/conv.rs
@@ -70,6 +70,67 @@ impl crate::Module for Conv1d {
     }
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ConvTranspose1dConfig {
+    pub padding: usize,
+    pub output_padding: usize,
+    pub stride: usize,
+    pub dilation: usize,
+    // TODO: support groups.
+}
+
+impl Default for ConvTranspose1dConfig {
+    fn default() -> Self {
+        Self {
+            padding: 0,
+            output_padding: 0,
+            stride: 1,
+            dilation: 1,
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct ConvTranspose1d {
+    weight: Tensor,
+    bias: Option<Tensor>,
+    config: ConvTranspose1dConfig,
+}
+
+impl ConvTranspose1d {
+    pub fn new(weight: Tensor, bias: Option<Tensor>, config: ConvTranspose1dConfig) -> Self {
+        Self {
+            weight,
+            bias,
+            config,
+        }
+    }
+
+    pub fn config(&self) -> &ConvTranspose1dConfig {
+        &self.config
+    }
+}
+
+impl crate::Module for ConvTranspose1d {
+    fn forward(&self, x: &Tensor) -> Result<Tensor> {
+        let x = x.conv_transpose1d(
+            &self.weight,
+            self.config.padding,
+            self.config.output_padding,
+            self.config.stride,
+            self.config.dilation,
+        )?;
+        match &self.bias {
+            None => Ok(x),
+            Some(bias) => {
+                let b = bias.dims1()?;
+                let bias = bias.reshape((1, b, 1, 1))?;
+                Ok(x.broadcast_add(&bias)?)
+            }
+        }
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct Conv2dConfig {
     pub padding: usize,
@@ -241,6 +302,39 @@ pub fn conv1d(
     Ok(Conv1d::new(ws, Some(bs), cfg))
 }
 
+pub fn conv_transpose1d(
+    in_channels: usize,
+    out_channels: usize,
+    kernel_size: usize,
+    cfg: ConvTranspose1dConfig,
+    vb: crate::VarBuilder,
+) -> Result<ConvTranspose1d> {
+    let bound = 1. / (out_channels as f64 * kernel_size as f64).sqrt();
+    let init = crate::Init::Uniform {
+        lo: -bound,
+        up: bound,
+    };
+    let ws = vb.get_with_hints((in_channels, out_channels, kernel_size), "weight", init)?;
+    let bs = vb.get_with_hints(out_channels, "bias", init)?;
+    Ok(ConvTranspose1d::new(ws, Some(bs), cfg))
+}
+
+pub fn conv_transpose1d_no_bias(
+    in_channels: usize,
+    out_channels: usize,
+    kernel_size: usize,
+    cfg: ConvTranspose1dConfig,
+    vb: crate::VarBuilder,
+) -> Result<ConvTranspose1d> {
+    let bound = 1. / (out_channels as f64 * kernel_size as f64).sqrt();
+    let init = crate::Init::Uniform {
+        lo: -bound,
+        up: bound,
+    };
+    let ws = vb.get_with_hints((in_channels, out_channels, kernel_size), "weight", init)?;
+    Ok(ConvTranspose1d::new(ws, None, cfg))
+}
+
 pub fn conv2d(
     in_channels: usize,
     out_channels: usize,