33 lines
890 B
Mathematica
33 lines
890 B
Mathematica
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function k = findrows(A, b)
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%FINDROWS Find indices of a given row within a matrix.
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%
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% FINDROWS(A, B) returns a column vector with the indices of the rows
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% in the matrix A that are identical to the row vector B. If no rows
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% in A are identical to B, an empty vector is returned.
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%
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% The methods uses a for-loop, but it uses less memory and is in many
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% cases a lot faster than the vectorized methods
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%
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% find( all( A == repmat(b, size(A, 1), 1), 2 ) )
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% find( all( A == b(ones(size(A, 1), 1),:), 2 ) )
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%
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% See also FIND, FINDCOLS.
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% Author: Peter J. Acklam
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% Time-stamp: 2002-03-03 13:51:15 +0100
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% E-mail: pjacklam@online.no
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% URL: http://home.online.no/~pjacklam
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if isempty(A)
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k = [];
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return
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end
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k = find( A(:,1) == b(1));
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top = size(A, 2);
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for j = 2:top
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k = k(A(k,j) == b(j));
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if isempty(k)
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return
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end
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end
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