# HG changeset patch
# User jwe
# Date 1191447428 0
# Node ID 09a89fb42c09a3528e303652ac919507fb6ffa9f
# Parent  f359defe99ffff78662ca56219dfb9c06c023728
[project @ 2007-10-03 21:36:42 by jwe]

diff --git a/scripts/ChangeLog b/scripts/ChangeLog
--- a/scripts/ChangeLog
+++ b/scripts/ChangeLog
@@ -1,6 +1,6 @@
 2007-10-03  Quentin Spencer  <qspencer@ieee.org>
 
-	* linear-algebra/norm.m: Special case vector 1-norm.
+	* linear-algebra/norm.m: Special case vector 1-norm and 2-norm.
 
 2007-10-03  David Bateman  <dbateman@free.fr>
 
diff --git a/scripts/linear-algebra/norm.m b/scripts/linear-algebra/norm.m
--- a/scripts/linear-algebra/norm.m
+++ b/scripts/linear-algebra/norm.m
@@ -95,6 +95,11 @@
           retval = min (abs (x));
 	elseif (p == 1)
 	  retval = sum (abs (x));
+	elseif (p == 2)
+          if (iscomplex (x))
+            x = abs (x);
+          endif
+          retval = sqrt (sum (x .* x));
         else
           retval = sum (abs (x) .^ p) ^ (1/p);
         endif
@@ -138,6 +143,7 @@
 %!assert(norm(x,"fro"), 10);
 %!assert(norm(x), 10);
 %!assert(norm([1e200, 1]), 1e200);
+%!assert(norm([3+4i, 3-4i, sqrt(31)]), 9, -4*eps);
 %!shared m
 %! m = magic (4);
 %!assert(norm(m,1), 34);