supdeq_extremal

% SUpDEq - Spatial Upsampling by Directional Equalization

 function [gridData, Npoints, Nmax] = supdeq_extremal(N)

 This function returns an extremal sampling grid with azimuth and 
 elevation in degree plus the respective sampling weights.
 The nodes for 1 <= N <= 100 are from 
 https://web.maths.unsw.edu.au/~rsw/Sphere/Extremal/New/index.html

 Output:
 gridData      - Q x 3 matrix where the first column holds the azimuth, the 
                 second the elevation, and the third the sampling weights.
 Npoints       - Total number of sampling points / nodes [(N+1)^2]
 Nmax          - Highest stable grid order  

 Input:
 N             - Spatial order of the extremal grid. 

 Dependencies: -

 (C) 2020 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 [gridData, Npoints, Nmax] = supdeq_extremal(N)
0004 %
0005 % This function returns an extremal sampling grid with azimuth and
0006 % elevation in degree plus the respective sampling weights.
0007 % The nodes for 1 <= N <= 100 are from
0008 % https://web.maths.unsw.edu.au/~rsw/Sphere/Extremal/New/index.html
0009 %
0010 % Output:
0011 % gridData      - Q x 3 matrix where the first column holds the azimuth, the
0012 %                 second the elevation, and the third the sampling weights.
0013 % Npoints       - Total number of sampling points / nodes [(N+1)^2]
0014 % Nmax          - Highest stable grid order
0015 %
0016 % Input:
0017 % N             - Spatial order of the extremal grid.
0018 %
0019 % Dependencies: -
0020 %
0021 % (C) 2020 by JMA, Johannes M. Arend
0022 %             TH Köln - University of Applied Sciences
0023 %             Institute of Communications Engineering
0024 %             Department of Acoustics and Audio Signal Processing
0025 
0026 function [gridData, Npoints, Nmax] = supdeq_extremal(N)
0027 
0028 if nargin == 0
0029     error('Please specify the desired spatial order N!');
0030 elseif N <= 0
0031     error('Sorry, but N >= 1 is mandatory');
0032 elseif N > 100
0033     error('Sorry, but we only have extremal grids up to N = 100');
0034 else
0035     % Load nodes from materials
0036     load('extremalNodes_1_100.mat');
0037     
0038     %Get respective grid data already in correct format
0039     gridData = extremalNodes{N};
0040     
0041     %Write other variables
0042     Npoints = size(gridData,1);
0043     Nmax = N;
0044     
0045 end
0046 
0047 end
0048