21 lines
552 B
Matlab
21 lines
552 B
Matlab
function writeij(filename, A)
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%-----------------------------------------------------------------------------
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% writeij('filename', A):
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% Writes to file 'filename' a sparse matrix A in IJ format.
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%-----------------------------------------------------------------------------
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fid=fopen(filename,'w');
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nrows = size(A,1);
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fprintf(fid,'%d %d %d %d\n', 0, nrows-1, 0, nrows-1);
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% the 'find' function does things in column order, so use A^T
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[J,I,V]=find(A');
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B(1,:) = I' - 1;
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B(2,:) = J' - 1;
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B(3,:) = V';
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fprintf(fid,'%d %d %.10e\n', B);
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fclose(fid);
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