From bb791dbac576f8459d522bd14b07afa50c298739 Mon Sep 17 00:00:00 2001
From: David Protzman <NotTelling@NoThanks.Poop>
Date: Sat, 11 Jun 2022 12:55:31 -0400
Subject: [PATCH] Added functions for mean and var

---
 .../gr-droneid/include/droneid/misc_utils.h   |  9 ++++
 gnuradio/gr-droneid/lib/misc_utils.cc         | 43 +++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/gnuradio/gr-droneid/include/droneid/misc_utils.h b/gnuradio/gr-droneid/include/droneid/misc_utils.h
index 1d809f3..8f58489 100644
--- a/gnuradio/gr-droneid/include/droneid/misc_utils.h
+++ b/gnuradio/gr-droneid/include/droneid/misc_utils.h
@@ -46,6 +46,15 @@ namespace gr {
             static std::vector<std::complex<float>> create_zc_sequence(double sample_rate, uint32_t root);
             static std::vector<std::complex<float>> conj(const std::vector<std::complex<float>> & input);
 
+            static std::complex<float> mean(const std::vector<std::complex<float>> & samples);
+            static float var(const std::vector<std::complex<float>> & samples);
+            static float var_no_mean(const std::vector<std::complex<float>> & samples);
+
+            static std::complex<float> mean(const std::complex<float> * samples, uint32_t sample_count);
+            static float var(const std::complex<float> * samples, uint32_t sample_count);
+
+            static float var_no_mean(const std::complex<float> * samples, uint32_t sample_count);
+
             static void write(const std::string & path, const void * element, uint32_t element_size, uint32_t element_count);
             static void write(const std::string & path, const std::vector<uint32_t> & elements);
             static void write_samples(const std::string &path, const std::complex<float> * samples, uint32_t element_count);
diff --git a/gnuradio/gr-droneid/lib/misc_utils.cc b/gnuradio/gr-droneid/lib/misc_utils.cc
index c896453..b95343d 100644
--- a/gnuradio/gr-droneid/lib/misc_utils.cc
+++ b/gnuradio/gr-droneid/lib/misc_utils.cc
@@ -341,6 +341,49 @@ namespace gr {
             return bits;
         }
 
+        std::complex<float> misc_utils::mean(const std::vector<std::complex<float>> &samples) {
+            return mean(&samples[0], samples.size());
+        }
+
+        float misc_utils::var(const std::vector<std::complex<float>> &samples) {
+            return var(&samples[0], samples.size());
+        }
+
+        std::complex<float> misc_utils::mean(const std::complex<float> *const samples, const uint32_t sample_count) {
+            auto sum = std::accumulate(samples, samples + sample_count, std::complex<float>{0, 0});
+            return sum / static_cast<float>(sample_count);
+        }
+
+        float misc_utils::var(const std::complex<float> *const samples, uint32_t sample_count) {
+            const auto mean_val = mean(samples, sample_count);
+            const auto recip = 1.0f / static_cast<float>(sample_count - 1);
+            float var_val = 0;
+
+            for (uint32_t idx = 0; idx < sample_count; idx++) {
+                const auto sample = samples[idx] - mean_val;
+                var_val += (static_cast<float>(std::pow(sample.real(), 2) + std::pow(sample.imag(), 2))) * recip;
+            }
+
+            return var_val;
+        }
+
+        float misc_utils::var_no_mean(const std::complex<float> *samples, uint32_t sample_count) {
+            const auto recip = 1.0f / static_cast<float>(sample_count - 1);
+            float var_val = 0;
+
+            for (uint32_t idx = 0; idx < sample_count; idx++) {
+                const auto & sample = samples[idx];
+                var_val += (static_cast<float>(std::pow(sample.real(), 2) + std::pow(sample.imag(), 2))) * recip;
+            }
+
+            return var_val;
+        }
+
+        float misc_utils::var_no_mean(const std::vector<std::complex<float>> &samples) {
+            return var_no_mean(&samples[0], samples.size());
+        }
+
+
     } /* namespace droneid */
 } /* namespace gr */