MATLAB: How to find matrix in a matrix

matrix

i have matrix a and b. matrix b is created from matrix a components(rows in this case). now i want to find out from which row of matrix a did matrix b created?

for example:

a=[4 5 7;5 8 9;6 3 1;9 8 5;7 6 5]

b=[4 5 7;6 3 1;9 8 5]

answer:

1;3;4

Best Answer

Use the command ismember(...,'rows')

Related Solutions

MATLAB: How to find a subset matrix in the main matrix and build a new matrix

I assume that the order of the rows in C don't matter:

[~,~, ib] = intersect(A, B(:, 1:5), 'rows'); %find rows of A in B
ids = B(ib, 6);                              %get the ID of those rows
C = B(ismember(B(:, 6), ids), :);            %get rows whose ID match

MATLAB: Matrix

m=[1 2 3;1 1 1;4 5 8;4 5 8;1 1 1;1 1 1;1 1 1;1 1 1;1 1 1;1 1 1;1 1 1;1 1 1;4 5 8;7 8 5; 47 9 5;7 8 5;5 322 5;7 8 55];

variant 1

[a b n] = unique(m,'rows','first');
[id id] = sort(b);
out1 = a(id,:);

variant 2

[a b n] = unique(m,'rows','first');
[id id] = sort(b);
t = accumarray(n,ones(numel(n),1)) == 1;
a2 = a(id,:);
out2 = a2(t(id),:);

Best Answer

Related Solutions

MATLAB: How to find a subset matrix in the main matrix and build a new matrix

MATLAB: Matrix

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