Show column which starts with certain numbers
3 views (last 30 days)
Show older comments
Hi, i have matrix size 500x500. And i need to find column which starts with vector [1 2]'. Only one column in whole matrix starts with these two certains numbers. The matrix looks something like this
[1 1 1 1 1]
[1 2 3 4 5]
[1 2 3 4 5]
I need function that tells me column number two starts with 1 and second value is 2.
Thanks for help!
0 Comments
Accepted Answer
Cedric
on 12 Apr 2013
If your matrix is named M, you can do
col = M(1,:) == 1 & M(2,:) == 2 ;
to get a vector of logicals indicating the relevant column, and
find(col)
to get the column number.
More Answers (1)
Youssef Khmou
on 12 Apr 2013
Edited: Youssef Khmou
on 12 Apr 2013
hi, try :
a=rand(500);
a(1:2,312)=[1 2]; % for example the column 312 starts with [1 2]
b=a(1:2,:);
test=[1 2]';
for n=1:length(b)
diff(n)=norm(b(:,n)-test);
end
Index=find(diff==0);
Index is the number of the column,
0 Comments
See Also
Categories
Find more on Matrices and Arrays 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!