I want to extract rows from my matrix that have a specific value in the second column.

I want to take all of the rows from a matrix that have a 1 in the second column and create a new matrix with these rows.

[Kavita Guddad]

x=[1 2 3 5;2 3 4 5;2 1 3 4;2 1 3 2 ];
y=[];
for i=1:size(x,1)
    if (x(i,2)==1)
        y=[y;x(i,:)];
    end
end
disp(x)

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

disp(y)

     2     1     3     4
     2     1     3     2

Answer 1

[Kavita Guddad]

Hope this code does your job.

x=[1 2 3 5;2 3 4 5;2 1 3 4;2 1 3 2 ];

y=[];

for i=1:size(x,1)

if (x(i,2)==1)

y=[y;x(i,:)];

end

end

disp(x)

disp(y)

Answer 2

[Abhas]

Hi Philip,

We can use logical indexing to select only the rows where the second column has a value of 1. The below code can solve your query:

% Sample input matrix
inputMatrix = [2, 1, 3; 
               4, 1, 6; 
               7, 0, 9; 
               1, 1, 2; 
               8, 1, 5];

% Find rows with a 1 in the second column
rowsWithOne = inputMatrix(inputMatrix(:, 2) == 1, :);

Hope this helps!