[Commit-gnuradio] [gnuradio] 02/07: random-analog: fixed reseed issue

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jcorgan pushed a commit to branch master
in repository gnuradio.

commit a09f44a82ec9c8f8932f815f9b5f90127d1edbe2
Author: Johannes Demel <address@hidden>
Date:   Mon Sep 28 11:00:27 2015 +0200

    random-analog: fixed reseed issue
---
 gnuradio-runtime/include/gnuradio/random.h       |  2 +-
 gnuradio-runtime/lib/math/random.cc              | 22 ++++++++++++------
 gnuradio-runtime/python/gnuradio/gr/qa_random.py | 29 ++++++++++++------------
 gr-analog/lib/random_uniform_source_X_impl.cc.t  |  4 ++--
 gr-analog/lib/random_uniform_source_X_impl.h.t   |  2 +-
 5 files changed, 33 insertions(+), 26 deletions(-)

diff --git a/gnuradio-runtime/include/gnuradio/random.h 
b/gnuradio-runtime/include/gnuradio/random.h
index c5761d7..2167247 100644
--- a/gnuradio-runtime/include/gnuradio/random.h
+++ b/gnuradio-runtime/include/gnuradio/random.h
@@ -66,7 +66,7 @@ namespace gr {
     void set_integer_limits(const int minimum, const int maximum);
 
     /*!
-     * Uniform random integers in the range set by 'set_integer_limits'.
+     * Uniform random integers in the range set by 'set_integer_limits' [min, 
max).
      */
     int ran_int();
 
diff --git a/gnuradio-runtime/lib/math/random.cc 
b/gnuradio-runtime/lib/math/random.cc
index b35dfa1..5e16c96 100644
--- a/gnuradio-runtime/lib/math/random.cc
+++ b/gnuradio-runtime/lib/math/random.cc
@@ -48,13 +48,14 @@ namespace gr {
   {
     d_gauss_stored = false; // set gasdev (gauss distributed numbers) on 
calculation state
 
-    // Setup random number generator
-    d_rng = new boost::mt19937;
+    // Setup random number generators
+    d_rng = new boost::mt19937; // random numbers are generated here.
+    d_uniform = new boost::uniform_real<float>; // map random number to 
distribution
+    d_integer_dis = new boost::random::uniform_int_distribution<>(0, 1); // 
another "mapper"
+    d_generator = NULL; // MUST be reinstantiated on every call to reseed.
+    d_integer_generator = NULL; // MUST be reinstantiated on everytime d_rng 
or d_integer_dis is changed.
     reseed(seed); // set seed for random number generator
-    d_uniform = new boost::uniform_real<float>;
-    d_integer_dis = new boost::random::uniform_int_distribution<>(min_integer, 
max_integer - 1);
-    d_generator = new boost::variate_generator<boost::mt19937&, 
boost::uniform_real<float> > (*d_rng,*d_uniform); // create number generator in 
[0,1) from boost.random
-    d_integer_generator = new boost::variate_generator<boost::mt19937&, 
boost::random::uniform_int_distribution<> >(*d_rng, *d_integer_dis);
+    set_integer_limits(min_integer, max_integer);
   }
 
   random::~random()
@@ -72,10 +73,14 @@ namespace gr {
   void
   random::reseed(unsigned int seed)
   {
-    //FIXME: method without effect after c'tor.
     if(seed==0) d_seed = static_cast<unsigned int>(std::time(0));
     else d_seed = seed;
     d_rng->seed(d_seed);
+    // reinstantiate generators. Otherwise reseed doesn't take effect.
+    delete d_generator;
+    d_generator = new boost::variate_generator<boost::mt19937&, 
boost::uniform_real<float> > (*d_rng,*d_uniform); // create number generator in 
[0,1) from boost.random
+    delete d_integer_generator;
+    d_integer_generator = new boost::variate_generator<boost::mt19937&, 
boost::random::uniform_int_distribution<> >(*d_rng, *d_integer_dis);
   }
 
   void
@@ -87,6 +92,9 @@ namespace gr {
     d_integer_generator = new boost::variate_generator<boost::mt19937&, 
boost::random::uniform_int_distribution<> >(*d_rng, *d_integer_dis);
   }
 
+  /*!
+   * Uniform random integers in the range set by 'set_integer_limits' [min, 
max).
+   */
   int
   random::ran_int(){
     return (*d_integer_generator)();
diff --git a/gnuradio-runtime/python/gnuradio/gr/qa_random.py 
b/gnuradio-runtime/python/gnuradio/gr/qa_random.py
index 6e32189..d3e5410 100644
--- a/gnuradio-runtime/python/gnuradio/gr/qa_random.py
+++ b/gnuradio-runtime/python/gnuradio/gr/qa_random.py
@@ -38,39 +38,38 @@ class test_random(gr_unittest.TestCase):
             self.assertLess(value, 1)
             self.assertGreaterEqual(value, 0)
 
-    # Check reseed method (init with time and seed as fix number)
-    def test_2(self):
+    # Same seed should yield same random values.
+    def test_2_same_seed(self):
         num = 5
-
-        rndm0 = gr.random(42)  # init with time
-        rndm1 = gr.random(42)  # init with fix seed
+        # Init with fixed seed.
+        rndm0 = gr.random(42)
+        rndm1 = gr.random(42)
         for k in range(num):
             x = rndm0.ran1()
             y = rndm1.ran1()
             self.assertEqual(x, y)
 
+    # reseed should yield same numbers.
+    def test_003_reseed(self):
+        num = 5
         x = np.zeros(num)
         y = np.zeros(num)
-        rndm0 = gr.random(42)  # init with fix seed 1
-        for k in range(num):
-            x[k] = rndm0.ran1()
-        rndm1.reseed(43)  # init with fix seed 2
+        rndm = gr.random(43)  # init with fix seed 1
         for k in range(num):
-            y[k] = rndm0.ran1()
+            x[k] = rndm.ran1()
+        rndm.reseed(43)  # init with fix seed 2
         for k in range(num):
-            self.assertNotEqual(x[k], y[k])
+            y[k] = rndm.ran1()
+        self.assertFloatTuplesAlmostEqual(x, y)
 
-    def test_003_integer(self):
+    def test_004_integer(self):
         nitems = 100000
         minimum = 2
         maximum = 42
-
         rng = gr.random(1, minimum, maximum)
-
         rnd_vals = np.zeros(nitems, dtype=int)
         for i in range(nitems):
             rnd_vals[i] = rng.ran_int()
-
         self.assertGreaterEqual(minimum, np.min(rnd_vals))
         self.assertLess(np.max(rnd_vals), maximum)
 
diff --git a/gr-analog/lib/random_uniform_source_X_impl.cc.t 
b/gr-analog/lib/random_uniform_source_X_impl.cc.t
index a93f887..98af5d0 100644
--- a/gr-analog/lib/random_uniform_source_X_impl.cc.t
+++ b/gr-analog/lib/random_uniform_source_X_impl.cc.t
@@ -52,7 +52,7 @@ namespace gr {
     }
 
     int
-    @IMPL_NAME@::random_int()
+    @IMPL_NAME@::random_value()
     {
       return d_rng->ran_int();
     }
@@ -65,7 +65,7 @@ namespace gr {
       @TYPE@ *out = (@address@hidden)output_items[0];
 
       for(int i = 0; i < noutput_items; i++){
-        *out++ = (@TYPE@) random_int();
+        *out++ = (@TYPE@) random_value();
       }
 
       // Tell runtime system how many output items we produced.
diff --git a/gr-analog/lib/random_uniform_source_X_impl.h.t 
b/gr-analog/lib/random_uniform_source_X_impl.h.t
index 289ee3c..67fcfc9 100644
--- a/gr-analog/lib/random_uniform_source_X_impl.h.t
+++ b/gr-analog/lib/random_uniform_source_X_impl.h.t
@@ -45,7 +45,7 @@ namespace gr {
            gr_vector_const_void_star &input_items,
            gr_vector_void_star &output_items);
 
-      int random_int();
+      int random_value();
     };
 
   } /* namespace filter */