5 files changed, 125 insertions, 9 deletions
diff --git a/gnuradio-core/src/lib/filter/Makefile.am b/gnuradio-core/src/lib/filter/Makefile.am
index 669461632..14800cd94 100644
--- a/gnuradio-core/src/lib/filter/Makefile.am
+++ b/gnuradio-core/src/lib/filter/Makefile.am
@@ -230,6 +230,7 @@ libfilter_qa_la_common_SOURCES = 	\
 	qa_gr_fir_fff.cc		\
 	qa_gr_fir_ccc.cc		\
 	qa_gr_fir_scc.cc		\
+	qa_gr_rotator.cc		\
 	qa_gri_mmse_fir_interpolator.cc	\
 	qa_gri_mmse_fir_interpolator_cc.cc	
 
@@ -317,6 +318,7 @@ noinst_HEADERS = 			\
 	qa_gr_fir_fff.h			\
 	qa_gr_fir_ccc.h			\
 	qa_gr_fir_scc.h			\
+	qa_gr_rotator.h			\
 	qa_gri_mmse_fir_interpolator.h	\
 	qa_gri_mmse_fir_interpolator_cc.h	
 
diff --git a/gnuradio-core/src/lib/filter/gr_rotator.h b/gnuradio-core/src/lib/filter/gr_rotator.h
index ccc08c9c2..cb8f21a40 100644
--- a/gnuradio-core/src/lib/filter/gr_rotator.h
+++ b/gnuradio-core/src/lib/filter/gr_rotator.h
@@ -1,6 +1,6 @@
 /* -*- c++ -*- */
 /*
- * Copyright 2003 Free Software Foundation, Inc.
+ * Copyright 2003,2008 Free Software Foundation, Inc.
  * 
  * This file is part of GNU Radio
  * 
@@ -28,21 +28,24 @@
 class gr_rotator {
   gr_complex	d_phase;
   gr_complex	d_phase_incr;
+  unsigned int	d_counter;
 
  public:
-  gr_rotator () : d_phase (1), d_phase_incr (0) { }
+  gr_rotator () : d_phase (1), d_phase_incr (1), d_counter(0) { }
 
-  void set_phase (gr_complex phase)     { d_phase = phase; }
-  void set_phase_incr (gr_complex incr) { d_phase_incr = incr; }
+  void set_phase (gr_complex phase)     { d_phase = phase / abs(phase); }
+  void set_phase_incr (gr_complex incr) { d_phase_incr = incr / abs(incr); }
 
   gr_complex rotate (gr_complex in){
-    d_phase *= d_phase_incr;	// incr our phase (complex mult == add phases)
+    d_counter++;
 
-    d_phase /= abs(d_phase);	// ensure multiplication is rotation
-				// FIXME.  This is expensive.  Maybe workaround using
-				// double precision complex???
+    gr_complex z = in * d_phase;    // rotate in by phase
+    d_phase *= d_phase_incr;	    // incr our phase (complex mult == add phases)
 
-    return in * d_phase;	// rotate in by phase
+    if ((d_counter % 512) == 0)
+      d_phase /= abs(d_phase);	    // Normalize to ensure multiplication is rotation
+
+    return z;
   }
 
 };
diff --git a/gnuradio-core/src/lib/filter/qa_filter.cc b/gnuradio-core/src/lib/filter/qa_filter.cc
index e2fa72add..878d48023 100644
--- a/gnuradio-core/src/lib/filter/qa_filter.cc
+++ b/gnuradio-core/src/lib/filter/qa_filter.cc
@@ -35,6 +35,7 @@
 #include <qa_dotprod.h>
 #include <qa_gri_mmse_fir_interpolator.h>
 #include <qa_gri_mmse_fir_interpolator_cc.h>
+#include <qa_gr_rotator.h>
 
 CppUnit::TestSuite *
 qa_filter::suite ()
@@ -49,6 +50,7 @@ qa_filter::suite ()
   s->addTest (qa_gr_fir_ccf::suite ());
   s->addTest (qa_gri_mmse_fir_interpolator::suite ());
   s->addTest (qa_gri_mmse_fir_interpolator_cc::suite ());
+  s->addTest (qa_gr_rotator::suite ());
 
   return s;
 }
diff --git a/gnuradio-core/src/lib/filter/qa_gr_rotator.cc b/gnuradio-core/src/lib/filter/qa_gr_rotator.cc
new file mode 100644
index 000000000..ce71a3d88
--- /dev/null
+++ b/gnuradio-core/src/lib/filter/qa_gr_rotator.cc
@@ -0,0 +1,70 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2002 Free Software Foundation, Inc.
+ * 
+ * This file is part of GNU Radio
+ * 
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ * 
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include <cppunit/TestAssert.h>
+#include <qa_gr_rotator.h>
+#include <gr_rotator.h>
+#include <stdio.h>
+#include <cmath>
+#include <gr_expj.h>
+
+
+// error vector magnitude
+__attribute__((unused)) static float
+error_vector_mag(gr_complex a, gr_complex b) 
+{
+  return abs(a-b);
+}
+
+void
+qa_gr_rotator::t1 ()
+{
+  static const unsigned	int N = 100000;
+
+  gr_rotator	r;
+
+  double phase_incr = 2*M_PI / 1003;
+  double phase = 0;
+
+  // Old code: We increment then return the rotated value, thus we need to start one tick back
+  // r.set_phase(gr_complex(1,0) * conj(gr_expj(phase_incr)));
+
+  r.set_phase(gr_complex(1,0));
+  r.set_phase_incr(gr_expj(phase_incr));
+
+  for (unsigned i = 0; i < N; i++){
+    gr_complex expected = gr_expj(phase);
+    gr_complex actual = r.rotate(gr_complex(1, 0));
+
+#if 0
+    float evm = error_vector_mag(expected, actual);
+    printf("[%6d] expected: (%8.6f, %8.6f)  actual: (%8.6f, %8.6f)  evm: %8.6f\n",
+	   i, expected.real(), expected.imag(), actual.real(), actual.imag(), evm);
+#endif
+
+    CPPUNIT_ASSERT_COMPLEXES_EQUAL(expected, actual, 0.0001);
+
+    phase += phase_incr;
+    if (phase >= 2*M_PI)
+      phase -= 2*M_PI;
+  }
+}
diff --git a/gnuradio-core/src/lib/filter/qa_gr_rotator.h b/gnuradio-core/src/lib/filter/qa_gr_rotator.h
new file mode 100644
index 000000000..2cc6006aa
--- /dev/null
+++ b/gnuradio-core/src/lib/filter/qa_gr_rotator.h
@@ -0,0 +1,39 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2008 Free Software Foundation, Inc.
+ * 
+ * This file is part of GNU Radio
+ * 
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ * 
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+#ifndef _QA_GR_ROTATOR_H_
+#define _QA_GR_ROTATOR_H_
+
+#include <cppunit/extensions/HelperMacros.h>
+#include <cppunit/TestCase.h>
+
+class qa_gr_rotator : public CppUnit::TestCase {
+
+  CPPUNIT_TEST_SUITE (qa_gr_rotator);
+  CPPUNIT_TEST (t1);
+  CPPUNIT_TEST_SUITE_END ();
+
+ private:
+  void t1 ();
+
+};
+
+#endif /* _QA_GR_ROTATOR_H_ */