how to swap rows of a matrix using command linalg::swapRow(A, 1, 2)

i need to swap two rows of a matrix.. how can i use the command linalg::swapRow(A, 1, 2)

Answer 1

[Walter Roberson]

feval(symengine, 'linalg::swapRow', A, 1, 2)

The output of this will be a symbolic matrix. If your matrix is numeric, then you should double() the result of the feval() to get back to numeric.

However... unless you are poking into the MuPAD engine, you are better off writing a small function:

function A = swapRow(A, row1, row2)
  A([row2, row1], :) = A([row1, row2], :);

Answer 2

[Neel Shah]

i want to swap rows of 3*3 matrix

i.e. first row become last

second row become second last

[Walter Roberson]

You can do

A([3 2 1],:) = A;

or

A = flipud(A);

This swaps the first and last row, leaving the middle row where it is.

[Rakib Seemanto]

how can I swap 6x6 matrix middle two rows.A = [ 1 2 3;4 5 6;7 8 9;10 11 12;13 14 15;16 17 18]

The output will be:B = [ 1 2 3;4 5 6;10 11 12;7 8 9;13 14 15;16 17 18]

[Walter Roberson]

A([4 5],:) = A([5 4],:);

[Rakib Seemanto]

thanks man