How to delete rows with values 0 from matrix

Question

Simon Spielmann 2023-5-1

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1955854-how-to-delete-rows-with-values-0-from-matrix

评论： Simon Spielmann 2023-5-1

Hello,

I have matrix A which looks like

A = [0 0 0; 0 0 0; 5 1 0; 0 0 0; 1 0 3; 5 9 5; 0 0 0]

I am trying delete all rows in which all values are 0 from matrix A to get:

A = [5 1 0; 1 0 3; 5 9 5]

I used this.

for i = 1:length(A(:,1))
    while A(i,1) == 0  && A(i,2) == 0 && A(i,3) == 0
        A(i,:) = [];
    end
end

At the end it gives me matrix A but also it gives me a error:

'Index in position 1 exceeds array bounds. Index must not exceed 4.' but do not know why...

2 个评论
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VBBV 2023-5-1

A = [0 0 0;  0 0 0;  5 1 0;  0 0 0; 1 0 3;  5 9 5;  0 0 0]
A = 7×3
     0     0     0
     0     0     0
     5     1     0
     0     0     0
     1     0     3
     5     9     5
     0     0     0
i = 1;
while i <= length(A)       
    if isequal(A(i,1),0)  & isequal(A(i,2), 0)  & isequal(A(i,3), 0)
        A(i,:) = [];   
        % tricky part lies in next line
        i = i-1;
    end    
    i = i+1 ;   
end
A
A = 3×3
     5     1     0
     1     0     3
     5     9     5

Simon Spielmann 2023-5-1

Than you a lot, it really helps!

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Answer 1

KSSV 2023-5-1

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1955854-how-to-delete-rows-with-values-0-from-matrix#answer_1226604

A = [0 0 0;  0 0 0;  5 1 0;  0 0 0; 1 0 3;  5 9 5;  0 0 0]
A = 7×3
   0     0
   0     0
   1     0
   0     0
   0     3
   9     5
   0     0
A(~any(A,2),:) = []
A = 3×3
   1     0
   0     3
   9     5