MATLAB: How to check if any row has 0

rows

If I have matrix A=

     0     0     0     5
     1     1     4     3
     1     3     4     5
     2     0     0     5

I need to find that rows which has 0.

A result should show rows 1 and 4, which there are some zeros.

Could anyone help me?!

Best Answer

>> idx = any(A==0,2) % logical index
idx =
     1
     0
     0
     1
>> find(idx) % subscript index
ans =
     1
     4

Related Solutions

MATLAB: 3>2>1 returns logical 0

The basic problem is that you are attempting two logical relations simultaneously: MATLAB's relational operators are binary operators, so they only support one comparison at once. In summary:

X<A<Y     % is NOT valid for comparing A against X and Y
X<A & A<Y % This compares A with both X and Y

In MATLAB logical relational operators follow the standard rules of operator precedence. Look at this example carefully:

>> 3<4<2
ans =
     1

The output is true, so does this mean that 4<2 ? Of course not, we just have to remember the operator precedence rules, just like in high school. This is evaluated according to those rules as:

>> (3<4)<2
ans =
     1

where

>> 3<4
ans =
     1

So 3<4<2 is actually equivalent to 1<2, which is of course very true:

>> 1<2
ans =
      1

MATLAB: Sort matrix to get the row and column position of sorted matrix

[~,idx] = sort(M(:), 'descend');
idx(M(:)==0) = [];
[row, col] = ind2sub(size(M), idx);
indexes = [row col];

Result:

Best Answer

Related Solutions

MATLAB: 3>2>1 returns logical 0

MATLAB: Sort matrix to get the row and column position of sorted matrix

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