From d63975562b2f4a18648ebd9c39d63165cf65d8d9 Mon Sep 17 00:00:00 2001
From: kortschak <dan.kortschak@adelaide.edu.au>
Date: Fri, 11 Mar 2016 11:04:36 +1030
Subject: [PATCH 1/3] mat64: remove stale TODO

This is now covered in the package level documentation and addressed in
code.
---
 mat64/dense.go  | 16 +++++++---------
 mat64/matrix.go |  3 ++-
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/mat64/dense.go b/mat64/dense.go
index 33d46cf..88f4a0a 100644
--- a/mat64/dense.go
+++ b/mat64/dense.go
@@ -327,7 +327,8 @@ func (m *Dense) Reset() {
 }
 
 // Clone makes a copy of a into the receiver, overwriting the previous value of
-// the receiver. The clone operation does not make any restriction on shape.
+// the receiver. The clone operation does not make any restriction on shape and
+// will not cause shadowing.
 //
 // See the Cloner interface for more information.
 func (m *Dense) Clone(a Matrix) {
@@ -343,11 +344,6 @@ func (m *Dense) Clone(a Matrix) {
 	switch aU := aU.(type) {
 	case RawMatrixer:
 		amat := aU.RawMatrix()
-		// TODO(kortschak): Consider being more precise with determining whether a and m are aliases.
-		// The current approach is that all RawMatrixers are considered potential aliases.
-		// Note that below we assume that non-RawMatrixers are not aliases; this is not necessarily
-		// true, but cases where it is not are not sensible. We should probably fix or document
-		// this though.
 		mat.Data = make([]float64, r*c)
 		if trans {
 			for i := 0; i < r; i++ {
@@ -361,13 +357,15 @@ func (m *Dense) Clone(a Matrix) {
 			}
 		}
 	default:
-		mat.Data = use(m.mat.Data, r*c)
-		m.mat = mat
+		mat.Data = make([]float64, r*c)
+		w := *m
+		w.mat = mat
 		for i := 0; i < r; i++ {
 			for j := 0; j < c; j++ {
-				m.set(i, j, a.At(i, j))
+				w.set(i, j, a.At(i, j))
 			}
 		}
+		*m = w
 		return
 	}
 	m.mat = mat
diff --git a/mat64/matrix.go b/mat64/matrix.go
index 12da4e1..af3654c 100644
--- a/mat64/matrix.go
+++ b/mat64/matrix.go
@@ -112,7 +112,8 @@ type RawColViewer interface {
 }
 
 // A Cloner can make a copy of a into the receiver, overwriting the previous value of the
-// receiver. The clone operation does not make any restriction on shape.
+// receiver. The clone operation does not make any restriction on shape and will not cause
+// shadowing.
 type Cloner interface {
 	Clone(a Matrix)
 }

From 6be0ffe893e0d6cb883eb42a24832c0d78752d54 Mon Sep 17 00:00:00 2001
From: kortschak <dan.kortschak@adelaide.edu.au>
Date: Fri, 11 Mar 2016 11:57:25 +1030
Subject: [PATCH 2/3] mat64: add Vector fast path to Clone

---
 mat64/dense.go | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mat64/dense.go b/mat64/dense.go
index 88f4a0a..ded3f0f 100644
--- a/mat64/dense.go
+++ b/mat64/dense.go
@@ -356,6 +356,12 @@ func (m *Dense) Clone(a Matrix) {
 				copy(mat.Data[i*c:(i+1)*c], amat.Data[i*amat.Stride:i*amat.Stride+c])
 			}
 		}
+	case *Vector:
+		amat := aU.mat
+		mat.Data = make([]float64, aU.n)
+		blas64.Copy(aU.n,
+			blas64.Vector{Inc: amat.Inc, Data: amat.Data},
+			blas64.Vector{Inc: 1, Data: mat.Data})
 	default:
 		mat.Data = make([]float64, r*c)
 		w := *m

From 05edb4948f0b174984516cd4edd9cd04466f24d6 Mon Sep 17 00:00:00 2001
From: kortschak <dan.kortschak@adelaide.edu.au>
Date: Fri, 11 Mar 2016 12:10:48 +1030
Subject: [PATCH 3/3] mat64: add Vector fast path to Copy

---
 mat64/dense.go | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/mat64/dense.go b/mat64/dense.go
index ded3f0f..6e6c141 100644
--- a/mat64/dense.go
+++ b/mat64/dense.go
@@ -408,6 +408,19 @@ func (m *Dense) Copy(a Matrix) (r, c int) {
 				copy(m.mat.Data[i*m.mat.Stride:i*m.mat.Stride+c], amat.Data[i*amat.Stride:i*amat.Stride+c])
 			}
 		}
+	case *Vector:
+		var n, stride int
+		if trans {
+			n = c
+			stride = 1
+		} else {
+			n = r
+			stride = m.mat.Stride
+		}
+		amat := aU.mat
+		blas64.Copy(n,
+			blas64.Vector{Inc: amat.Inc, Data: amat.Data},
+			blas64.Vector{Inc: stride, Data: m.mat.Data})
 	default:
 		for i := 0; i < r; i++ {
 			for j := 0; j < c; j++ {