how can i combine two vector into one vector by the follwoing pattern ( and not use "For" Loop which take a lot of time , since this vector is a Million of elements ):
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example :
a1 [ 1,2,3,4,5,6......]
a2 [ x,y,z,w,v,b,n,....]
a3 = [ 1,x,2,y,3,z,4,w,5,v,.....]
many thanks for the help
2 Comments
Answers (2)
Michael Haderlein
on 7 Oct 2014
Edited: Michael Haderlein
on 7 Oct 2014
One option
a3=[a1; a2];
a3=a3(:)';
This only works if a1, a2 are line vectors. Otherwise, take the transpose of each in the first line.
3 Comments
sravankumar v
on 11 Aug 2017
can you please tell me how can i arrange the elements of three matrices alternatively in to another matrix using for loop?
Orion
on 7 Oct 2014
Hi,
the command a3=[a1; a2]; will put the a2 vector at the end of the a1 vector and not alternate the value of a1 and a2.
to make the pattern asked, you should do something like :
a1 = 1:10;
a2 = 21:30;
a3 = zeros(1,length(a1)*2);
a3(1:2:end-1) = a1;
a3(2:2:end) = a2;
this will work very fast even for a million element vector.
4 Comments
Chris Liu
on 29 Nov 2018
Thanks for the answer. So what's the case if and are matrix? When I do like that,
just change a3 = zeros(1,size(a1,2)*2);
it reports error: "unable to perform assignment because the left and right sides have a different number of elements." Thanks.
Chris Liu
on 29 Nov 2018
sorry for my bad, I miss the zero matrix. It works fine under ur answer. thx
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