how to check if two elements are in a row of a matrix?

Question

Pramod Devireddy 2015-7-1

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回答： Andrei Bobrov 2015-7-2

suppose

A=[1 2;
5;
9]
B=[1 3 5 6;
2 4 7;
6 4 8;
2 3 4].

In this case 1,2 of 1st row of A are present in 2nd row B, similarly all rows of A have to check with rows of B, and create a matrix &nbsp C=[6 9] &nbsp which are not present in any row of B.

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Answer 1

the cyclist 2015-7-2

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Here is one clumsy way:

A=[1 2;
   4 5;
   6 9];
B=[1 3 5 6;
   1 2 4 7;
   5 6 4 8;
   1 2 3 4];
rowCountA = size(A,1);
rowCountB = size(B,1);
this_row_of_A_is_in_B = false(rowCountA,1);
for nb = 1:rowCountB
    this_row_of_A_is_in_B = this_row_of_A_is_in_B | all(ismember(A,B(nb,:)),2);
end
rows_of_A_that_are_not_in_B = A(not(this_row_of_A_is_in_B),:)

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Azzi Abdelmalek 2015-7-2

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This doesn't work for this example

A=[1 2;
5;
9
8]
B=[1 3 5 6;
2 4 7;
6 4 8;
2 3 4]

the cyclist 2015-7-2

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By my understanding of the problem, the output for these inputs should be

[6 9;
 1 8]

because there is no row of B that has [6,9] and also no row that has [1,8].

That output is what my code has, so it behaves as I intended, and how I interpreted the question. (But, of course, I could be interpreting incorrectly.)

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Answer 2

Azzi Abdelmalek 2015-7-2

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编辑：Azzi Abdelmalek 2015-7-2

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A=[1 2;
  4 5;
  6 9
  1 8]
B=[1 3 5 6;
  1 2 4 7;
  5 6 4 8;
  1 2 3 4]
out=[];
for ii=1:size(A,1)
  for jj=1:size(B,1)
      id=all(ismember(A(ii,:),B(jj,:)));
      if id==1
          out(end+1,:)=A(ii,:);
          break
      end
  end
end
out=setdiff(A,out,'rows')

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Answer 3

Andrei Bobrov 2015-7-2

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ii = fullfact([size(A,1),size(B,1)]);
t = arrayfun(@(i1)sum(ismember(B(ii(i1,2),:),A(ii(i1,1),:))),(1:size(ii,1))') < 2;
C = A(accumarray(ii(:,1),t) == 4,:);