changeset 560:ab7fabe2af5d

fix some bugs I left in IHC one-cap and just-hwr modes

--- a/trunk/matlab/bmm/carfac/CARFAC_Cross_Couple.m	Tue Apr 10 05:40:18 2012 +0000
+++ b/trunk/matlab/bmm/carfac/CARFAC_Cross_Couple.m	Mon Apr 23 21:02:04 2012 +0000
@@ -1,28 +1,27 @@
 function AGC_state = CARFAC_Cross_Couple(AGC_coeffs, AGC_state);
 
 n_ears = length(AGC_state);
-mix_coeffs = AGC_coeffs.AGC_mix_coeffs;
-n_stages = length(mix_coeffs);
-
-% now cross-ear mix the stages that updated (leading stages at phase 0):
-for stage = 1:n_stages
-  if AGC_state(1).decim_phase(stage) > 0
-    break  % all recently updated stages are finished
-  else
-    mix_coeff = mix_coeffs(stage);
-    if mix_coeff > 0  % Typically stage 1 has 0 so no work on that one.
-      this_stage_sum = 0;
-      % sum up over the ears and get their mean:
-      for ear = 1:n_ears
-        stage_state = AGC_state(ear).AGC_memory(:, stage);
-        this_stage_sum = this_stage_sum + stage_state;
-      end
-      this_stage_mean = this_stage_sum / n_ears;
-      % now move them all toward the mean:
-      for ear = 1:n_ears
-        stage_state = AGC_state(ear).AGC_memory(:, stage);
-        AGC_state(ear).AGC_memory(:, stage) = ...
-          stage_state +  mix_coeff * (this_stage_mean - stage_state);
+if n_ears > 1
+  % now cross-ear mix the stages that updated (leading stages at phase 0):
+  for stage = 1:AGC_coeffs.n_AGC_stages
+    if AGC_state(1).decim_phase(stage) > 0
+      break  % all recently updated stages are finished
+    else
+      mix_coeff = AGC_coeffs.AGC_mix_coeffs(stage);
+      if mix_coeff > 0  % Typically stage 1 has 0 so no work on that one.
+        this_stage_sum = 0;
+        % sum up over the ears and get their mean:
+        for ear = 1:n_ears
+          stage_state = AGC_state(ear).AGC_memory(:, stage);
+          this_stage_sum = this_stage_sum + stage_state;
+        end
+        this_stage_mean = this_stage_sum / n_ears;
+        % now move them all toward the mean:
+        for ear = 1:n_ears
+          stage_state = AGC_state(ear).AGC_memory(:, stage);
+          AGC_state(ear).AGC_memory(:, stage) = ...
+            stage_state +  mix_coeff * (this_stage_mean - stage_state);
+        end
       end
     end
   end

--- a/trunk/matlab/bmm/carfac/CARFAC_Design.m	Tue Apr 10 05:40:18 2012 +0000
+++ b/trunk/matlab/bmm/carfac/CARFAC_Design.m	Mon Apr 23 21:02:04 2012 +0000
@@ -333,8 +333,9 @@
 function IHC_coeffs = CARFAC_DesignIHC(IHC_params, fs, n_ch)
 
 if IHC_params.just_hwr
-  IHC_coeffs = struct('just_hwr', 1);
-  saturation_output = 10;  % HACK: assume some max out
+    IHC_coeffs = struct( ...
+      'n_ch', n_ch, ...
+      'just_hwr', 1);
 else
   if IHC_params.one_cap
     ro = 1 / CARFAC_Detect(2);  % output resistance
@@ -346,7 +347,6 @@
     r0 = 1 / CARFAC_Detect(0);
     current = 1 / (ri + r0);
     cap_voltage = 1 - current * ri;
-      IHC_coeffs.rest_output = IHC_out;
     IHC_coeffs = struct( ...
       'n_ch', n_ch, ...
       'just_hwr', 0, ...
@@ -362,7 +362,8 @@
       'cap_voltage', IHC_coeffs.rest_cap, ...
       'lpf1_state', 0, ...
       'lpf2_state', 0, ...
-      'ihc_accum', 0);  else
+      'ihc_accum', 0);  
+  else
     ro = 1 / CARFAC_Detect(2);  % output resistance
     c2 = IHC_params.tau2_out / ro;
     r2 = IHC_params.tau2_in / c2;

--- a/trunk/matlab/bmm/carfac/CARFAC_IHC_Step.m	Tue Apr 10 05:40:18 2012 +0000
+++ b/trunk/matlab/bmm/carfac/CARFAC_IHC_Step.m	Mon Apr 23 21:02:04 2012 +0000
@@ -26,7 +26,7 @@
 just_hwr = coeffs.just_hwr;
 
 if just_hwr
-  ihc_out = max(0, filters_out);
+  ihc_out = min(2, max(0, filters_out));  % limit it for stability
   state.ihc_accum = state.ihc_accum + ihc_out;
 else
   conductance = CARFAC_Detect(filters_out);  % detect with HWR or so
@@ -48,13 +48,11 @@
 
   % smooth it twice with LPF:
 
+  ihc_out = ihc_out * coeffs.output_gain;
   state.lpf1_state = state.lpf1_state + coeffs.lpf_coeff * ...
     (ihc_out - state.lpf1_state);
-
   state.lpf2_state = state.lpf2_state + coeffs.lpf_coeff * ...
     (state.lpf1_state - state.lpf2_state);
-
-  ihc_out = state.lpf2_state * coeffs.output_gain - coeffs.rest_output;
-  
+  ihc_out = state.lpf2_state - coeffs.rest_output;
   state.ihc_accum = state.ihc_accum + ihc_out;  % for where decimated output is useful
 end

--- a/trunk/matlab/bmm/carfac/CARFAC_Stage_g.m	Tue Apr 10 05:40:18 2012 +0000
+++ b/trunk/matlab/bmm/carfac/CARFAC_Stage_g.m	Mon Apr 23 21:02:04 2012 +0000
@@ -26,5 +26,5 @@
 c0 = CAR_coeffs.c0_coeffs;
 h  = CAR_coeffs.h_coeffs;
 zr = CAR_coeffs.zr_coeffs;
-r  = r1 - zr.*extra_damping;  % HACK??? or use sin(ff*theta) instead of c?
+r  = r1 - zr.*extra_damping;
 g  = (1 - 2*r.*a0 + r.^2) ./ (1 - 2*r.*a0 + h.*r.*c0 + r.^2);