Merge pull request #310 from nilgoyette/row_vector_cross_product

Row vector cross product

src/core/matrix.rs

@@ -879,7 +879,7 @@ impl<N: Scalar + Ring, R: Dim, C: Dim, S: Storage<N, R, C>> Matrix<N, R, C, S> {
 
                 *res.get_unchecked_mut(0, 0) = ay * bz - az * by;
                 *res.get_unchecked_mut(0, 1) = az * bx - ax * bz;
-                *res.get_unchecked_mut(0, 2) = az * bx - ax * bz;
+                *res.get_unchecked_mut(0, 2) = ax * by - ay * bx;
 
                 res
             }

tests/core/matrix.rs

@@ -7,7 +7,7 @@ use alga::linear::FiniteDimInnerSpace;
 use na::{self,
          DVector, DMatrix,
          Vector1, Vector2, Vector3, Vector4, Vector5, Vector6,
-         RowVector4, RowVector5,
+         RowVector3, RowVector4, RowVector5,
          Matrix1, Matrix2, Matrix3, Matrix4, Matrix5, Matrix6,
          Matrix2x3, Matrix3x2, Matrix3x4, Matrix4x3, Matrix2x4, Matrix4x5, Matrix4x6,
          MatrixMN};
@@ -382,6 +382,23 @@ fn simple_product() {
     assert_eq!(a * b * c, vec![a, b, c].into_iter().product());
 }
 
+#[test]
+fn cross_product_vector_and_row_vector() {
+    let v1 = Vector3::new(1.0, 2.0, 3.0);
+    let v2 = Vector3::new(1.0, 5.0, 7.0);
+    let column_cross = v1.cross(&v2);
+    assert_eq!(column_cross, Vector3::new(-1.0, -4.0, 3.0));
+
+    let v1 = RowVector3::new(1.0, 2.0, 3.0);
+    let v2 = RowVector3::new(1.0, 5.0, 7.0);
+    let row_cross = v1.cross(&v2);
+    assert_eq!(row_cross, RowVector3::new(-1.0, -4.0, 3.0));
+
+    assert_eq!(
+        Vector3::new(1.0, 1.0, 0.0).cross(&Vector3::new(-0.5, 17.0, 0.0)).transpose(),
+        RowVector3::new(1.0, 1.0, 0.0).cross(&RowVector3::new(-0.5, 17.0, 0.0)));
+}
+
 #[test]
 fn simple_scalar_conversion() {
     let a = Matrix2x3::new(1.0, 2.0, 3.0,