From: Michael Orlitzky <michael@orlitzky.com>
Date: Mon, 25 Feb 2013 14:35:00 +0000 (-0500)
Subject: Add the is_upper_triangular() function and its tests.
X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=542e0bbc0bcde79e1366d4280cc0637cd43586d1;p=octave.git

Add the is_upper_triangular() function and its tests.
---

diff --git a/is_upper_triangular.m b/is_upper_triangular.m
new file mode 100644
index 0000000..b78991d
--- /dev/null
+++ b/is_upper_triangular.m
@@ -0,0 +1,4 @@
+function isUT = is_upper_triangular(A)
+  ## Returns true if ``A`` is upper triangular, false otherwise.
+  isUT = isequal(A, triu(A));
+end
diff --git a/tests/is_upper_triangular_tests.m b/tests/is_upper_triangular_tests.m
new file mode 100644
index 0000000..209edde
--- /dev/null
+++ b/tests/is_upper_triangular_tests.m
@@ -0,0 +1,16 @@
+A = eye(5);
+unit_test_equals("eye(5) is upper-triangular", ...
+		 true, ...
+		 is_upper_triangular(A));
+
+A = [1, 2, 3; ...
+     0, 4, 5; ...
+     0, 0, 6];
+unit_test_equals("An upper-triangular matrix is upper-triangular", ...
+		 true, ...
+		 is_upper_triangular(A));
+
+
+unit_test_equals("A lower-triangular matrix is not upper-triangular", ...
+		 false, ...
+		 is_upper_triangular(A'));