[bug fix] throw warning if no channel labels for connectivity_features

Author: otoolej

CHANGELOG.md

@@ -7,7 +7,14 @@ in the git logs.
 ### Changed 
 ### Removed
 ### Fixed
+- Bug fix for `connectivity_features`; was: if channel labels (cell of strings) are empty
+  then would assume (incorrectly) only 2 channels and would use index [1,2] for left,right
+  hemisphere; now: if no channel labels throw warning
 ### Added
+- Check in `spectral_features`: is `L_window` longer than signal (and if so throw
+  warning)?
+
+
 
 
 ## [0.4.3] - 2020-04-22

connectivity_features/connectivity_features.m

@@ -40,7 +40,7 @@
 % John M. O' Toole, University College Cork
 % Started: 13-04-2016
 %
-% last update: Time-stamp: <2019-01-09 15:58:25 (otoolej)>
+% last update: Time-stamp: <2020-08-17 16:49:56 (otoolej)>
 %-------------------------------------------------------------------------------
 function featx = connectivity_features(x, Fs, feat_name, params_st, ch_labels)
 if(nargin<2), error('need 2 input arguments'); end
@@ -76,17 +76,18 @@
     N_freq_bands = 1;
 end
 
-
-if(N_channels>2  && ~isempty(ch_labels))
+if(~isempty(ch_labels))
+    % find left and right channels:
     [ileft, iright] = channel_hemispheres(ch_labels);
     ipairs = channel_hemisphere_pairs(ch_labels);    
-elseif(N_channels == 2)
-    % if no channel labels then guess:
-    ileft = 1; iright = 2;
-    ipairs = [1 2]';
+else
+    warning('REQUIRED: channel names for coherence function.');
+    featx = NaN;
+    return;
 end
 
 
+
 switch feat_name
   case 'connectivity_BSI'
     %---------------------------------------------------------------------

spectral_features/spectral_features.m

@@ -26,7 +26,7 @@
 % John M. O' Toole, University College Cork
 % Started: 07-04-2016
 %
-% last update: Time-stamp: <2020-04-22 17:27:24 (otoolej)>
+% last update: Time-stamp: <2020-08-17 16:53:32 (otoolej)>
 %-------------------------------------------------------------------------------
 function featx=spectral_features(x,Fs,feat_name,params_st)
 if(nargin<2), error('need 2 input arguments'); end
@@ -48,50 +48,57 @@
 total_freq_bands=params_st.total_freq_bands;
 
 
+if(length(x) < (params_st.L_window * Fs))
+    warning('SPECTRAL features: signal length < window length; set shorter L_window');
+    warning('SPECTRAL features: not calculating spectral features.');
+    featx = NaN;
+    return;
+end
+
 
 switch feat_name
   case {'spectral_power','spectral_relative_power'}
-        %---------------------------------------------------------------------
-        % use periodogram to estimate spectral power 
-        %---------------------------------------------------------------------
-        params_st.method='periodogram';
-        [pxx,itotal_bandpass,f_scale,N,fp]=gen_spectrum(x,Fs,params_st,1);
-        pxx=pxx.*Fs;
-
-        Nh=length(pxx);
-        
-        if(DBplot)
-            figure(1); clf; hold all;
-            plot(fp,20*log10(pxx));
-        end
-        
-        if(strcmp(feat_name,'spectral_relative_power'))
-            pxx_total=sum( pxx(itotal_bandpass) )/N;
+    %---------------------------------------------------------------------
+    % use periodogram to estimate spectral power 
+    %---------------------------------------------------------------------
+    params_st.method='periodogram';
+    [pxx,itotal_bandpass,f_scale,N,fp]=gen_spectrum(x,Fs,params_st,1);
+    pxx=pxx.*Fs;
+
+    Nh=length(pxx);
+    
+    if(DBplot)
+        figure(1); clf; hold all;
+        plot(fp,20*log10(pxx));
+    end
+    
+    if(strcmp(feat_name,'spectral_relative_power'))
+        pxx_total=sum( pxx(itotal_bandpass) )/N;
+    else
+        pxx_total=1;
+    end
+    
+    spec_pow=NaN(1,size(freq_bands,1));
+
+    for p=1:size(freq_bands,1)
+        if(p==1)
+            istart=ceil(freq_bands(p,1)*f_scale);
         else
-            pxx_total=1;
+            istart=ibandpass(end)-1;
         end
+        ibandpass=istart:floor(freq_bands(p,2)*f_scale);        
+        ibandpass=ibandpass+1;
+        ibandpass(ibandpass<1)=1; ibandpass(ibandpass>Nh)=Nh;    
 
-        spec_pow=NaN(1,size(freq_bands,1));
-
-        for p=1:size(freq_bands,1)
-            if(p==1)
-                istart=ceil(freq_bands(p,1)*f_scale);
-            else
-                istart=ibandpass(end)-1;
-            end
-            ibandpass=istart:floor(freq_bands(p,2)*f_scale);        
-            ibandpass=ibandpass+1;
-            ibandpass(ibandpass<1)=1; ibandpass(ibandpass>Nh)=Nh;    
-            
-            spec_pow(p)=sum( pxx(ibandpass) )/(N*pxx_total);            
-            
-            if(DBplot)
-                line([fp(ibandpass(1)) fp(ibandpass(1))],ylim,'color','k');        
-                line([fp(ibandpass(end)) fp(ibandpass(end))],ylim,'color','k');
-            end
-        end
-        featx=spec_pow;
+        spec_pow(p)=sum( pxx(ibandpass) )/(N*pxx_total);            
 
+        if(DBplot)
+            line([fp(ibandpass(1)) fp(ibandpass(1))],ylim,'color','k');        
+            line([fp(ibandpass(end)) fp(ibandpass(end))],ylim,'color','k');
+        end
+    end
+    featx=spec_pow;
+    
 
   case 'spectral_flatness'
     %---------------------------------------------------------------------
@@ -225,3 +232,6 @@
 
 
 
+
+end
+