From 7357bcf88dfd140ee15e48810b655b24011ef9ca Mon Sep 17 00:00:00 2001
From: "David F. Gleich" <dgleich@cs.ubc.ca>
Date: Wed, 25 Nov 2009 09:42:23 -0800
Subject: [PATCH] Fixed bug with root vertex for mst_prim and added regression
 test

---
 mst_prim.m           |  3 ++-
 test/test_main.m     |  1 +
 test/test_mst_prim.m | 21 +++++++++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)
 create mode 100644 test/test_mst_prim.m

diff --git a/mst_prim.m b/mst_prim.m
index a24e52c..1532882 100644
--- a/mst_prim.m
+++ b/mst_prim.m
@@ -24,11 +24,12 @@
 
 %  History:
 %  2009-05-02: Added example
+%  2009-11-25: Fixed bug with target 
 
 % TODO: Add example
 
 if ~exist('full','var') || isempty(full), full=0; end
-if ~exist('target','var') || isempty(full), u=1; end
+if ~exist('u','var') || isempty(u), u=1; end
 
 if isstruct(A), 
     rp=A.rp; ci=A.ci; ai=A.ai; 
diff --git a/test/test_main.m b/test/test_main.m
index 07354e8..dd12019 100644
--- a/test/test_main.m
+++ b/test/test_main.m
@@ -10,5 +10,6 @@
 test_examples
 % test_dijkstra % required for floydwarshall
 test_floydwarshall
+test_mst_prim
 
 end
diff --git a/test/test_mst_prim.m b/test/test_mst_prim.m
new file mode 100644
index 0000000..1c38ded
--- /dev/null
+++ b/test/test_mst_prim.m
@@ -0,0 +1,21 @@
+function test_mst_prim
+msgid = 'gaimc:mst_prim';
+load_gaimc_graph('clr-24-1');
+A(2,3) = 9; A(3,2) = 9;
+T = mst_prim(A); % root the tree at vertex 
+Ttrueijv = [
+     2     8     1     4     6     9     3     5     4     3     7     6     8     1     7     3
+     1     1     2     3     3     3     4     4     5     6     6     7     7     8     8     9
+     4     8     4     7     4     2     7     9     9     4     2     2     1     8     1     2 ];
+Ttrue = sparse(Ttrueijv(1,:),  Ttrueijv(2,:), Ttrueijv(3,:), 9,9);
+if nnz(T - Ttrue) ~= 0
+    error(msgid, 'mst_prim failed');
+end
+
+load_gaimc_graph('clr-24-1');
+T1 = mst_prim(A); % root the tree at vertex 
+T2 = mst_prim(A,[],5);
+T1T2diff = sparse(9,9); T1T2diff(2,3) = 8; T1T2diff(1,8) = -8;
+if nnz(triu(T1-T2)-T1T2diff) ~= 0
+    error(msgid, 'mst_prim failed rooted test');
+end