From e3b4bd0393f707ab3b1f4a96344c95ea32b30abc Mon Sep 17 00:00:00 2001
From: Fredrik Ekre <fredrik.ekre@chalmers.se>
Date: Thu, 31 Aug 2017 15:47:04 +0200
Subject: [PATCH] faster sparse(::Diagonal)

---
 base/sparse/sparsematrix.jl | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/base/sparse/sparsematrix.jl b/base/sparse/sparsematrix.jl
index c3304d34ad3471..3f1a1427583a7b 100644
--- a/base/sparse/sparsematrix.jl
+++ b/base/sparse/sparsematrix.jl
@@ -764,6 +764,11 @@ function sparse(B::Bidiagonal)
     return sparse([1:m;1:m-1],[1:m;2:m],[B.dv;B.ev], Int(m), Int(m)) # upper bidiagonal
 end
 
+function sparse(D::Diagonal)
+    m = length(D.diag)
+    return SparseMatrixCSC(m, m, [1:m; m+1], [1:m;], D.diag)
+end
+
 ## Transposition and permutation methods
 
 """