From: Michael Orlitzky <michael@orlitzky.com>
Date: Sun, 5 May 2013 01:11:13 +0000 (-0400)
Subject: Check for the easy case in rank_k_approximation().
X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=b39f6d3f6aaaebe891c09a8923547f25c2d43b84;p=octave.git

Check for the easy case in rank_k_approximation().
---

diff --git a/rank_k_approximation.m b/rank_k_approximation.m
index ff42f58..9883084 100644
--- a/rank_k_approximation.m
+++ b/rank_k_approximation.m
@@ -14,6 +14,15 @@ function Ak = rank_k_approximation(A,k)
   %
   %   - ``Ak`` -- The rank-k approximation to ``A``.
   %
+  [m,n] = size(A);
+
+  if (k >= min(m,n))
+    % We're keeping greater than or equal to the maximum number of
+    % singular values that can exist.
+    Ak = A;
+    return;
+  end
+
   [U, S, V] = svds(A, k);
   Ak = U*S*V';
 end