Obtain lines of a matrix according to its position.

Hi. Good day.

I hope you help me solve this problem.

I have a matrix A of size 4 X 18.

I have the positions of the lines(row) that interest me to know.

For example I have the positions of lines(row) 2 and 4 and now I am interested in "" taking out "" of the matrix A the values ​​of lines(row) 2 and 4 and with these values ​​forming a matrix B

A=[ 10 87 11 10 10 10 13 10 76 82 87 89 86 10 13 88 12 90

. 84 70 76 86 90 10 10 80 69 71 72 83 68 84 11 76 10 83

. 91 99 94 10 85 80 10 88 84 88 11 10 78 81 82 86 11 86

. 71 73 74 76 73 67 86 77 76 78 86 89 78 73 79 73 91 79 ];

This would be the matrix B

B=[84 70 76 86 90 10 10 80 69 71 72 83 68 84 11 76 10 83

. 71 73 74 76 73 67 86 77 76 78 86 89 78 73 79 73 91 79]

The actual matrix A I have is 720 X 18

Thank you.

Regards.

[Diana Mae Calde]

Matrix is equal m x n where m is number of rows and n is number of columns

A = 720 x18 and you want a specific row to be in B

B = A(2,:); for row 2

but if you need multiple of 2

size = size(A)

for n = 1:size(1)

B = A(n,:);

n = n + 2

end

[Ricardo Gutierrez]

Thank you for the solution.

Regards

Answer 1

[Stephen23]

All you need is some very basic indexing:

B = A([2,4],:)

Very basic MATLAB concepts, like how to use indexing, are explained in the introdutory tutorials:

https://www.mathworks.com/help/matlab/getting-started-with-matlab.html

https://matlabacademy.mathworks.com/

[Ricardo Gutierrez]

Thank you for the solution and advices

Regards