how to delete a row from a matrix

Question

nadia nadi 2015-10-25

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/250884-how-to-delete-a-row-from-a-matrix

编辑： Stephen23 2015-10-25

Dear,

I need to delete rows with all zeros from B and corresponding ones from b, where Bx>=b, so I wrote this code but I got error because of the index, can anyone check it for me please and if there is any faster way will be very helpful. Thanks in advance.

Nadia

B=[ 
     1     0     0     0     0     0     0          
     0     0     0     1     0     0     0          
     0     0     0     0     0     0     0    
     0     1     0     1     0     0     0     
     0     0     0     0     1     1     0     
     0     1     0     0     0     0     1    
     0     0     0     0     0     0     0   
     0     0     0     0     0     0     1    
     0     0     1     0     0     0     0];
 b=ones(size(B,1),1);
  for i=1:size(B,1)
     while B(i,:)==0
         B(i,:)=[]
        b(i,:)=[] 
     end
 end

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Jan 2015-10-25

The error is caused by running the for i loop until the original size of B, but B has been shortend already inside the loop.

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Answer 1

Stephen23 2015-10-25

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/250884-how-to-delete-a-row-from-a-matrix#answer_197254

编辑：Stephen23 2015-10-25

在 MATLAB Online 中打开

When you use vectorized code then this task is simple, and there is no need for complicated loops:

>>B(any(B,2),:)
ans =
   0     0     0     0     0     0
   0     0     1     0     0     0
   1     0     1     0     0     0
   0     0     0     1     1     0
   1     0     0     0     0     1
   0     0     0     0     0     1
   0     1     0     0     0     0