36 lines
771 B
Mathematica
36 lines
771 B
Mathematica
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function sys = blocks(varargin)
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% BLOCKS Internal function (Not used)
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%
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% BLOCKS(X1,X2,X3,X4) Tries to create a blocks-symmetric matrix
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%
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% Example: blocks(X1,X2,X3) creates [X1 X2;X' X3]
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% blocks(X1,X2,X3,X4,X5,X6) creates [X1 X2 X3;X2' X4 X5;X3' X5' X6]
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if rem(nargin,3)~=0
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error('The number of blocks in a block-symmetric matrix has to be a multiple of 3')
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end
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m = nargin;
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n = max(roots([1 1 -2*m]));
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k = 1;
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Z = zeros(n);
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for i = 1:n
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for j = i:n
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Z(i,j)=k;k = k+1;
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end
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end
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Z = (Z+Z')-diag(diag(Z));
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sys = [];
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for i = 1:n
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sysrow = [];
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for j = 1:1:n
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if j<i
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sysrow = [sysrow varargin{Z(i,j)}];
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else
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sysrow = [sysrow varargin{Z(i,j)}'];
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end
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end
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sys = [sys;sysrow];
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end
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