PyTorch: Fix SGD ValueError

Author: AnirudhDagar

.github/workflow_scripts/build_pytorch.sh

@@ -21,7 +21,7 @@ d2lbook build outputcheck tabcheck
 # Move aws copy commands for cache restore outside
 if [ "$DISABLE_CACHE" = "false" ]; then
   echo "Retrieving pytorch build cache from "$CACHE_DIR""
-  measure_command_time "aws s3 sync s3://preview.d2l.ai/"$CACHE_DIR"/"$REPO_NAME"-"$TARGET_BRANCH"/_build/eval_pytorch _build/eval_pytorch --delete --quiet --exclude 'data/*'"
+  measure_command_time "aws s3 sync s3://preview.d2l.ai/"$CACHE_DIR"/"$REPO_NAME"-"$TARGET_BRANCH"/_build/eval_pytorch/ _build/eval_pytorch/ --delete --quiet --exclude 'data/*'"
   echo "Retrieving pytorch slides cache from "$CACHE_DIR""
   aws s3 sync s3://preview.d2l.ai/"$CACHE_DIR"/"$REPO_NAME"-"$TARGET_BRANCH"/_build/slides _build/slides --delete --quiet --exclude 'data/*'
 fi

chapter_optimization/sgd.md

@@ -75,8 +75,8 @@ def f_grad(x1, x2):  # 目标函数的梯度
 def sgd(x1, x2, s1, s2, f_grad):
     g1, g2 = f_grad(x1, x2)
     # 模拟有噪声的梯度
-    g1 += d2l.normal(0.0, 1, (1,))
-    g2 += d2l.normal(0.0, 1, (1,))
+    g1 += d2l.normal(0.0, 1, (1,)).item()
+    g2 += d2l.normal(0.0, 1, (1,)).item()
     eta_t = eta * lr()
     return (x1 - eta_t * g1, x2 - eta_t * g2, 0, 0)
 ```