From 5f455396abe7da2ec96300c7b1ee31748f138752 Mon Sep 17 00:00:00 2001
From: Andrej Rode <mail@andrejro.de>
Date: Mon, 19 Mar 2018 23:19:02 +0100
Subject: analog: remove std::time(0) seed from gr::random if 0 is selected
Instead the default seed implemented in boost::random is used by
calling seed() without arguments
---
gnuradio-runtime/lib/math/random.cc | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
(limited to 'gnuradio-runtime/lib/math/random.cc')
diff --git a/gnuradio-runtime/lib/math/random.cc b/gnuradio-runtime/lib/math/random.cc
index 401ba89735..af90a33429 100644
--- a/gnuradio-runtime/lib/math/random.cc
+++ b/gnuradio-runtime/lib/math/random.cc
@@ -73,9 +73,12 @@ namespace gr {
void
random::reseed(unsigned int seed)
{
- if(seed==0) d_seed = static_cast<unsigned int>(std::time(0));
- else d_seed = seed;
- d_rng->seed(d_seed);
+ d_seed = seed;
+ if (d_seed == 0){
+ d_rng->seed();
+ } else {
+ 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
--
cgit v1.2.3
From 26ca54a29ad74ca3612db7433a855f4fd41f7d61 Mon Sep 17 00:00:00 2001
From: Andrej Rode <mail@andrejro.de>
Date: Mon, 19 Mar 2018 23:33:03 +0100
Subject: analog: improve readability of laplacian distribution
---
gnuradio-runtime/lib/math/random.cc | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
(limited to 'gnuradio-runtime/lib/math/random.cc')
diff --git a/gnuradio-runtime/lib/math/random.cc b/gnuradio-runtime/lib/math/random.cc
index af90a33429..cedaf4b97f 100644
--- a/gnuradio-runtime/lib/math/random.cc
+++ b/gnuradio-runtime/lib/math/random.cc
@@ -141,11 +141,12 @@ namespace gr {
float
random::laplacian()
{
- float z = ran1()-0.5;
- if(z>0) return -logf(1-2*z);
- else return logf(1+2*z);
+ float z = ran1();
+ if (z > 0.5f){
+ return -logf(2.0f * (1.0f - z) );
+ }
+ return logf(2 * z);
}
-
/*
* Copied from The KC7WW / OH2BNS Channel Simulator
* FIXME Need to check how good this is at some point
--
cgit v1.2.3