From 9a87e2360d46f7d926e9af647121528ff5b03c6f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Crozet?= <sebastien@crozet.re>
Date: Sun, 17 Apr 2016 13:20:58 +0200
Subject: [PATCH] Implement Outer for DVec. (#186)

Fix #181.
---
 src/structs/dvec.rs | 24 ++++++++++++++++++++++--
 tests/mat.rs        |  8 ++++++++
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/structs/dvec.rs b/src/structs/dvec.rs
index 4f31a273..ba8b27ec 100644
--- a/src/structs/dvec.rs
+++ b/src/structs/dvec.rs
@@ -7,7 +7,8 @@ use std::ops::{Add, Sub, Mul, Div, Neg, AddAssign, SubAssign, MulAssign, DivAssi
 use std::mem;
 use rand::{self, Rand};
 use num::{Zero, One};
-use traits::operations::{ApproxEq, Axpy, Mean};
+use structs::DMat;
+use traits::operations::{ApproxEq, Axpy, Mean, Outer};
 use traits::geometry::{Dot, Norm};
 use traits::structure::{Iterable, IterableMut, Indexable, Shape, BaseFloat, BaseNum, Cast};
 #[cfg(feature="arbitrary")]
@@ -57,7 +58,7 @@ impl<N> DVec<N> {
     /// Builds a vector filled with the results of a function applied to each of its component coordinates.
     #[inline(always)]
     pub fn from_fn<F: FnMut(usize) -> N>(dim: usize, mut f: F) -> DVec<N> {
-        DVec { at: (0..dim).map(|i| f(i)).collect() }
+        DVec { at: (0 .. dim).map(|i| f(i)).collect() }
     }
 
     /// The vector length.
@@ -74,6 +75,25 @@ impl<N> FromIterator<N> for DVec<N> {
     }
 }
 
+impl<N: Copy + BaseNum> Outer for DVec<N> {
+    type OuterProductType = DMat<N>;
+
+    #[inline]
+    fn outer(&self, other: &DVec<N>) -> DMat<N> {
+        let mut res = unsafe { DMat::new_uninitialized(self.at.len(), other.at.len()) };
+
+        for i in 0 .. self.at.len() {
+            for j in 0 .. other.at.len() {
+                unsafe {
+                    res.unsafe_set((i, j), self.unsafe_at(i) * other.unsafe_at(j));
+                }
+            }
+        }
+
+        res
+    }
+}
+
 #[cfg(feature="arbitrary")]
 impl<N: Arbitrary> Arbitrary for DVec<N> {
     fn arbitrary<G: Gen>(g: &mut G) -> DVec<N> {
diff --git a/tests/mat.rs b/tests/mat.rs
index 1eeefd9d..fce64edc 100644
--- a/tests/mat.rs
+++ b/tests/mat.rs
@@ -835,3 +835,11 @@ fn test_transpose_square_mat() {
         assert_eq!(&[0, 1, 2, 3], &mat.row_slice(i, 0, num_cols)[..]);
     }
 }
+
+#[test]
+fn test_outer_dvec() {
+    let vec = DVec::from_slice(5, &[ 1.0, 2.0, 3.0, 4.0, 5.0 ]);
+    let row = DMat::from_row_vec(1, 5, &vec[..]);
+
+    assert_eq!(row.transpose() * row, na::outer(&vec, &vec))
+}