Switch two row of matrix

How to switch two row of matrix? For example: matrix A is: 1 3 4; 2 4 5 and Y want to be 2 4 5; 1 3 4 ?

[Nikhil Sachan]

temp=A(2,:);

A(1,:)=A(2,:);

A(2,:)=temp;

%this will swap required rows

[madhan ravi]

A more efficient answer had been accepted 5 years ago.

[Tristan McRae]

omg savage

Answer 1

[Azzi Abdelmalek]

A=[1 3 4; 2 4 5]
A([1 2],:)=A([2 1],:)

[Evil Meet]

Thank you very much. U r awesome

[Kevin Moss]

can anyone explain the logic behind why/how this works?

[Andrey Piavkin]

this works pretty clear

we take first and second all the row and make it equal to second and first all the row

for example, if you wanted to switch the third and the first row, you should type like this:

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

where ':' at second place stands for taking all the columns and '[1 3]' stands for first and third row

Answer 2

[Pontus Vikstål]

This way might be even faster.

A = [1 3 4; 2 4 5]
x = [0 1;1 0];
A = x*A

Then there's also this way

A = [1 3 4; 2 4 5]
A = flip(A)

[madhan ravi]

If A has more than two rows this won’t work.

[Luis Mendez Lopez]

Yeah i will do that with my 600*600 matrix