Is it possible to add row vectors into a matrix with a for loop?
조회 수: 57 (최근 30일)
이전 댓글 표시
I wonder if it's possible to add rows of a matrix one at a time with a for loop? Example, if i initialize a blank matrix:
mat = [0 0 0];
and i have some dummy samples:
sample1 = [1 2 3];
sample2 = [4 5 6];
and i want to do something like:
for i=1:2
mat(i,:) = sample1;
end
so i would get:
mat = [1 2 3
4 5 6]
as the output. The idea is that what if i can't predefine the size of the matrix beforehand and that I'm not entirely sure how many sample will be there until the process ends? Is it possible in matlab?
댓글 수: 0
채택된 답변
Chris
2019년 8월 19일
편집: Chris
2019년 8월 19일
A loop is not needed for your simple demo
>> mat = [sample1; sample2]
mat =
1 2 3
4 5 6
But yes you can in general append to existing matrixies, it is best to preallocate when you can.
>> aa = [];
>> for ii = 1:5
aa(:,ii) = rand(3,1);
end
>> aa
aa =
0.90579 0.63236 0.54688 0.15761 0.48538
0.12699 0.09754 0.95751 0.97059 0.80028
0.91338 0.2785 0.96489 0.95717 0.14189
Note you have to define aa first. Also you need to append with consistent row/column lengths.
Edit: to prevent some future problems you might want to read:
댓글 수: 0
추가 답변 (0개)
참고 항목
카테고리
Help Center 및 File Exchange에서 Creating and Concatenating Matrices에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!