supdeq_calcEnergyPerOrder

% SUpDEq - Spatial Upsampling by Directional Equalization

 function results = supdeq_calcEnergyPerOrder( HRTFdataset, plotResults )

 This function calculates the energy of the SH-coefficients with respect
 to the transform order N. The function uses AKshEnergy, calculating  
 the energy using Parseval's theorem and normalizing by 1/(4*pi).

 Output:
 results               - Results struct with average energy per order N
                         for SH-coefficients of left/right ear

 Input:        
 testHRTFdataset       - Struct with (SH-coefficients) of the test 
                         HRTF dataset (for example the de-equalized HRTF set
                         or any other HRTF set like the referenceHRTFdataset) 
                         for the left (Hl_nm) and right (Hr_nm), channel/ear, 
                         absolute frequency scale f, transform order N, and FFToversize
 plotResults          -  plotResults true/false. Simple plot...
                         Default: false

 Dependencies: AKtools

 (C) 2018 by JMA, Johannes M. Arend
             TH Köln - University of Applied Sciences
             Institute of Communications Engineering
             Department of Acoustics and Audio Signal Processing

0001 %% SUpDEq - Spatial Upsampling by Directional Equalization
0002 %
0003 % function results = supdeq_calcEnergyPerOrder( HRTFdataset, plotResults )
0004 %
0005 % This function calculates the energy of the SH-coefficients with respect
0006 % to the transform order N. The function uses AKshEnergy, calculating
0007 % the energy using Parseval's theorem and normalizing by 1/(4*pi).
0008 %
0009 % Output:
0010 % results               - Results struct with average energy per order N
0011 %                         for SH-coefficients of left/right ear
0012 %
0013 % Input:
0014 % testHRTFdataset       - Struct with (SH-coefficients) of the test
0015 %                         HRTF dataset (for example the de-equalized HRTF set
0016 %                         or any other HRTF set like the referenceHRTFdataset)
0017 %                         for the left (Hl_nm) and right (Hr_nm), channel/ear,
0018 %                         absolute frequency scale f, transform order N, and FFToversize
0019 % plotResults          -  plotResults true/false. Simple plot...
0020 %                         Default: false
0021 %
0022 % Dependencies: AKtools
0023 %
0024 % (C) 2018 by JMA, Johannes M. Arend
0025 %             TH Köln - University of Applied Sciences
0026 %             Institute of Communications Engineering
0027 %             Department of Acoustics and Audio Signal Processing
0028 
0029 function results = supdeq_calcEnergyPerOrder( HRTFdataset, plotResults )
0030 
0031 if nargin < 2
0032     plotResults = false;
0033 end
0034 
0035 %% Calculate energy for SH-coefficients of letft and right ear
0036 
0037 [~,~,~,avgEperN_Hl_nm] = AKshEnergy(HRTFdataset.Hl_nm);
0038 [~,~,~,avgEperN_Hr_nm] = AKshEnergy(HRTFdataset.Hr_nm);
0039 
0040 %Write results struct
0041 results.avgEperN_Hl_nm = avgEperN_Hl_nm;
0042 results.avgEperN_Hr_nm = avgEperN_Hr_nm;
0043 results.N              = HRTFdataset.N;
0044 
0045 %% Plot if intended
0046 
0047 if plotResults
0048    figure;
0049    plot(0:results.N,10*log10(results.avgEperN_Hl_nm),'k','LineWidth',1.5);
0050    hold on;
0051    plot(0:results.N,10*log10(results.avgEperN_Hr_nm),'r','LineWidth',1.5);
0052    legend('Left','Right');
0053    grid on;
0054    title('Total Energy per Order N')
0055    xlabel('Order N')
0056    ylabel('Energy [dB]')
0057 end
0058 
0059 end
0060