How to replace data in a matrix by comparing from another matrix?
3 views (last 30 days)
Show older comments
I have a matrix A,
[1 5
2 6
3 6
4 7
5 6]
and I have another matrix B as
[1 2
1 3
1 4
1 5
2 3
2 4
3 4
3 5
4 5]
now i want to compare B with a and i want to replace 2nd column of B with A data for example,
[1 5
1 5
1 5
1 5
2 6
2 6
3 6
3 6
4 7]
in first column when there is 1 it will take the value of matrix A's second column data as 5 and when first column is having 2 it will take the value of 2 from matrix A.
please please help me.
0 Comments
Accepted Answer
David Sanchez
on 5 May 2015
for k=1:length(B)
x = A(:,1)==B(k,1);
B(k,2) = A(x,2);
end
B =
1 5
1 5
1 5
1 5
2 6
2 6
3 6
3 6
4 7
2 Comments
More Answers (2)
Andrei Bobrov
on 5 May 2015
Edited: Andrei Bobrov
on 5 May 2015
[lo,ii] = ismember(B(:,1),A(:,1));
out = B;
out(lo,2) = A(ii(lo),2);
3 Comments
Nobel Mondal
on 5 May 2015
Assuming, the 'a' matrix has unique values in the first column
for bRow= 1:size(b, 1)
aRow = find(a(:,1)==b(bRow,1), 1);
if ~isempty(aRow)
b(thisrow,2) = a(aRow,2);
end
end
See Also
Categories
Find more on Creating and Concatenating Matrices in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!