27 lines
836 B
Mathematica
27 lines
836 B
Mathematica
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%%*****************************************************************
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%% checkdense : identify the dense columns of a matrix
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%%
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%%*****************************************************************
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%% SDPT3: version 4.0
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%% Copyright (c) 1997 by
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%% K.C. Toh, M.J. Todd, R.H. Tutuncu
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%% Last Modified: 16 Sep 2004
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%%*****************************************************************
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function idxden = checkdense(A);
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[m,n] = size(A);
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idxden = [];
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nzratio = 1;
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if (m > 1000); nzratio = 0.20; end;
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if (m > 2000); nzratio = 0.10; end;
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if (m > 5000); nzratio = 0.05; end;
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if (nzratio < 1)
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nzcolA = sum(spones(A));
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idxden = find(nzcolA > nzratio*m);
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if (length(idxden) > max(200,0.1*n))
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idxden = [];
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end
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end
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%%********************************************************************
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