Mercurial > hg > octave-lyh

changeset 11030:231946a9ad55

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
make the result of r^m real when r > 0
author Jaroslav Hajek <highegg@gmail.com>
date Tue, 28 Sep 2010 13:56:10 +0200
parents 4ab04ea74b08
children d81b6144c4ba
files src/ChangeLog src/xpow.cc
diffstat 2 files changed, 17 insertions(+), 2 deletions(-) [+]
line wrap: on
line diff
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2010-09-28  Jaroslav Hajek  <highegg@gmail.com>
+
+	* xpow.cc (xpow (double, const Matrix&)): Ensure real result for
+	positive base.
+	(xpow (double, const Matrix&)): Likewise.
+
 2010-09-28  Jaroslav Hajek  <highegg@gmail.com>
 
 	* error.cc (interpreter_try): New function.
--- a/src/xpow.cc
+++ b/src/xpow.cc
@@ -123,7 +123,11 @@
             }
           ComplexDiagMatrix D (lambda);
 
-          retval = ComplexMatrix (Q * D * Q.inverse ());
+          ComplexMatrix C = Q * D * Q.inverse ();
+          if (a > 0)
+            retval = real (C);
+          else
+            retval = C;
         }
       else
         error ("xpow: matrix diagonalization failed");
@@ -1534,7 +1538,12 @@
             }
           FloatComplexDiagMatrix D (lambda);
 
-          retval = FloatComplexMatrix (Q * D * Q.inverse ());
+          FloatComplexMatrix C = Q * D * Q.inverse ();
+
+          if (a > 0)
+            retval = real (C);
+          else
+            retval = C;
         }
       else
         error ("xpow: matrix diagonalization failed");