update

Signed-off-by: Joe McCain III <jo3mccain@icloud.com>

tensor/src/impls/grad.rs

@@ -76,13 +76,14 @@ where
                             *store.entry(rhs.id()).or_insert(rhs.zeros_like()) += &grad;
                         }
                         BinaryOp::Mul => {
-                            *store.entry(lhs.id()).or_insert(lhs.zeros_like()) += &grad * rhs.as_ref();
-                            *store.entry(rhs.id()).or_insert(rhs.zeros_like()) += &grad * lhs.as_ref();
+                            *store.entry(lhs.id()).or_insert(lhs.zeros_like()) +=
+                                &grad * rhs.as_ref();
+                            *store.entry(rhs.id()).or_insert(rhs.zeros_like()) +=
+                                &grad * lhs.as_ref();
                         }
                         _ => todo!(),
                     },
                     TensorOp::Unary(_a, kind) => match kind {
-
                         _ => todo!(),
                     },
                     _ => {}

tensor/src/impls/reshape.rs

@@ -2,7 +2,7 @@
     Appellation: reshape <impls>
     Contrib: FL03 <jo3mccain@icloud.com>
 */
-use crate::prelude::IntoShape;
+use crate::prelude::{IntoShape, ShapeError, TensorResult};
 use crate::tensor::TensorBase;
 
 impl<T> TensorBase<T>
@@ -17,9 +17,14 @@ where
         unimplemented!()
     }
 
-    pub fn reshape(&self, shape: impl IntoShape) -> Self {
-        let _shape = shape.into_shape();
+    pub fn reshape(self, shape: impl IntoShape) -> TensorResult<Self> {
+        let mut tensor = self;
+        let shape = shape.into_shape();
+        if tensor.elements() != shape.elements() {
+            return Err(ShapeError::MismatchedElements.into());
+        }
 
-        unimplemented!()
+        tensor.layout.shape = shape;
+        Ok(tensor)
     }
 }

tensor/src/shape/error.rs

@@ -34,6 +34,7 @@ pub type ShapeResult<T = ()> = std::result::Result<T, ShapeError>;
 pub enum ShapeError {
     IncompatibleShapes,
     InvalidShape,
+    MismatchedElements,
 }
 
 unsafe impl Send for ShapeError {}

tensor/src/shape/mod.rs

@@ -28,6 +28,7 @@ where
 
 pub(crate) mod prelude {
     pub use super::dim::*;
+    pub use super::error::*;
     pub use super::shape::*;
     pub use super::stride::*;
     pub use super::IntoShape;

tensor/src/tensor.rs

@@ -58,6 +58,9 @@ impl<T> TensorBase<T> {
     pub fn from_vec(kind: TensorMode, shape: impl IntoShape, store: Vec<T>) -> Self {
         from_vec(kind, shape, store)
     }
+    pub fn elements(&self) -> usize {
+        self.layout.elements()
+    }
     /// Returns the unique identifier of the tensor.
     pub fn id(&self) -> TensorId {
         self.id

tensor/tests/backward.rs

@@ -15,10 +15,7 @@ fn test_backward() {
     let c = &a + &b;
     let grad = c.grad();
 
-    assert_eq!(
-        grad[&a.id()],
-        Tensor::ones(shape),
-    );
+    assert_eq!(grad[&a.id()], Tensor::ones(shape),);
     assert_eq!(grad[&b.id()], Tensor::ones(shape));
 
     let a = Tensor::<f64>::ones(shape).variable();

tensor/tests/composition.rs

@@ -16,6 +16,16 @@ fn test_tensor() {
     assert_ne!(&a, &b);
 }
 
+#[test]
+fn test_reshape() {
+    let shape = (2, 2);
+    let a = Tensor::<f64>::ones(shape);
+    let b = a.clone().reshape((4,)).unwrap();
+
+    assert_ne!(&a.shape(), &b.shape());
+    assert_eq!(&a.elements(), &b.elements());
+}
+
 #[test]
 fn test_arange() {
     let exp = Shape::from(10);