1 files changed, 68 insertions, 0 deletions
diff --git a/gr-digital/lib/digital_probe_density_b.cc b/gr-digital/lib/digital_probe_density_b.cc
new file mode 100644
index 000000000..6b83d2ddb
--- /dev/null
+++ b/gr-digital/lib/digital_probe_density_b.cc
@@ -0,0 +1,68 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2008,2010,2012 Free Software Foundation, Inc.
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <digital_probe_density_b.h>
+#include <gr_io_signature.h>
+#include <stdexcept>
+#include <iostream>
+
+digital_probe_density_b_sptr
+digital_make_probe_density_b(double alpha)
+{
+  return gnuradio::get_initial_sptr(new digital_probe_density_b(alpha));
+}
+
+digital_probe_density_b::digital_probe_density_b(double alpha)
+  : gr_sync_block("density_b",
+		  gr_make_io_signature(1, 1, sizeof(char)),
+		  gr_make_io_signature(0, 0, 0))
+{
+  set_alpha(alpha);
+  d_density = 1.0;
+}
+
+digital_probe_density_b::~digital_probe_density_b()
+{
+}
+
+int
+digital_probe_density_b::work(int noutput_items,
+			      gr_vector_const_void_star &input_items,
+			      gr_vector_void_star &output_items)
+{
+  const char *in = (const char *)input_items[0];
+
+  for (int i = 0; i < noutput_items; i++)
+    d_density = d_alpha*(double)in[i] + d_beta*d_density;
+
+  return noutput_items;
+}
+
+void
+digital_probe_density_b::set_alpha(double alpha)
+{
+  d_alpha = alpha;
+  d_beta = 1.0-d_alpha;
+}
+