diff trunk/carfac/car_coeffs.cc @ 668:933cf18d9a59

Fourth revision of Alex Brandmeyer's C++ implementation. Fixed more style issues, changed AGC structures to vectors, replaced FloatArray2d with vector<FloatArray>, implemented first tests using GTest to verify coefficients and monaural output against Matlab values (stored in aimc/carfac/test_data/). To run tests, change the path stored in carfac_test.h in TEST_SRC_DIR. Added CARFAC_GenerateTestData to the Matlab branch, fixed stage indexing in CARFAC_Cross_Couple.m to reflect changes in AGCCoeffs and AGCState structs.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/trunk/carfac/car_coeffs.cc	Wed May 22 21:30:02 2013 +0000
@@ -0,0 +1,47 @@
+//
+//  car_coeffs.cc
+//  CARFAC Open Source C++ Library
+//
+//  Created by Alex Brandmeyer on 5/18/13.
+//  Copyright (c) 2013 Alex Brandmeyer. All rights reserved.
+//
+
+#include "car_coeffs.h"
+
+void CARCoeffs::Design(const CARParams& car_params, const FPType fs,
+                        const FloatArray& pole_freqs) {
+  // TODO (alexbrandmeyer): verify acceptability of/documentation level needed
+  // for use of short intermediate variable names.
+  n_ch_ = pole_freqs.size();
+  velocity_scale_ = car_params.velocity_scale_;
+  v_offset_ = car_params.v_offset_;
+  r1_coeffs_.resize(n_ch_);
+  a0_coeffs_.resize(n_ch_);
+  c0_coeffs_.resize(n_ch_);
+  h_coeffs_.resize(n_ch_);
+  g0_coeffs_.resize(n_ch_);
+  FPType f = car_params.zero_ratio_ * car_params.zero_ratio_ - 1.0;
+  FloatArray theta = pole_freqs * ((2.0 * PI) / fs);
+  c0_coeffs_ = theta.sin();
+  a0_coeffs_ = theta.cos();
+  FPType ff = car_params.high_f_damping_compression_;
+  FloatArray x = theta / PI;
+  zr_coeffs_ = PI * (x - (ff * (x*x*x)));
+  FPType max_zeta = car_params.max_zeta_;
+  FPType min_zeta = car_params.min_zeta_;
+  r1_coeffs_ = (1.0 - (zr_coeffs_ * max_zeta));
+  FloatArray erb_freqs(n_ch_);
+  for (int ch=0; ch < n_ch_; ++ch) {
+    erb_freqs(ch) = ERBHz(pole_freqs(ch), car_params.erb_break_freq_,
+                          car_params.erb_q_);
+  }
+  FloatArray min_zetas = min_zeta + (0.25 * ((erb_freqs / pole_freqs) -
+                                             min_zeta));
+  zr_coeffs_ *= max_zeta - min_zetas;
+  h_coeffs_ = c0_coeffs_ * f;
+  FloatArray relative_undamping = FloatArray::Ones(n_ch_);
+  FloatArray r = r1_coeffs_ + (zr_coeffs_ * relative_undamping);
+  g0_coeffs_ = (1.0 - (2.0 * r * a0_coeffs_) + (r*r)) /
+                                        (1 - (2 * r * a0_coeffs_) +
+                                        (h_coeffs_ * r * c0_coeffs_) + (r*r));
+}
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