# Zero out values ​​from a specific row in a matrix

조회 수: 12(최근 30일)
Lev Mihailov 2022년 2월 24일
댓글: Jan 2022년 2월 24일
I create a matrix, I need to reset all values ​​​​above or below a certain line
c = randi([50 90],1,900); % rows in the matrix before or after which you need to reset everything
x = rand(100,900);
I would appreciate any help
##### 댓글 수: 1표시숨기기 없음
Jan 2022년 2월 24일
Does "reset" means, to set the value to 0? A small example with inputs and output would clarify this.

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### 채택된 답변

DGM 2022년 2월 24일
Depends if you want before or after. Since there's no specified mechanism to determine which, I'm assuming they're separate cases.
% a smaller array
sz = [10 10];
c = randi(round([0.5 0.9]*sz(1)),1,sz(2))
c = 1×10
5 5 8 8 7 6 5 7 7 7
x = rand(sz);
% above
xa = zeros(sz);
for col = 1:sz(2)
xa(c(col):end,col) = x(c(col):end,col);
end
xa
xa = 10×10
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.6705 0.3275 0 0 0 0 0.8203 0 0 0 0.3977 0.2444 0 0 0 0.2563 0.6388 0 0 0 0.3504 0.4670 0 0 0.8608 0.6775 0.7311 0.6058 0.9829 0.5098 0.2348 0.4727 0.5051 0.7958 0.2300 0.5589 0.2007 0.7440 0.6406 0.1086 0.3023 0.2689 0.6540 0.5244 0.9616 0.0880 0.9428 0.1761 0.6237 0.5623 0.7242 0.2876 0.3713 0.6931 0.6045 0.1354 0.0207 0.3005 0.6675 0.9878
% below
xb = zeros(sz);
for col = 1:sz(2)
xb(1:c(col),col) = x(1:c(col),col);
end
xb
xb = 10×10
0.2351 0.8935 0.6577 0.1085 0.7050 0.7653 0.5715 0.1200 0.3469 0.8277 0.8900 0.0832 0.3699 0.4257 0.3712 0.8449 0.8821 0.3460 0.0425 0.6749 0.7048 0.9170 0.8989 0.5342 0.1087 0.4904 0.3728 0.1454 0.6048 0.0438 0.9782 0.3588 0.9342 0.3823 0.5303 0.7890 0.3342 0.0637 0.2030 0.5178 0.6705 0.3275 0.4531 0.0285 0.0355 0.8376 0.8203 0.1705 0.6936 0.4366 0 0 0.6351 0.0355 0.8810 0.2563 0 0.7491 0.8071 0.5694 0 0 0.1182 0.9483 0.8608 0 0 0.6058 0.9829 0.5098 0 0 0.5051 0.7958 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

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