How do i reconstruct a matrix???

I have a matrix 2000x3 like this:

1 1 6

1 2 8

1 3 15

....

2 1 10

2 2 20

2 3 13

....

3 1 12

3 2 18

3 3 14

...

...

and i want to reconstruct like this:

1 1 6

1 2 8

1 3 15

....

2 3 13

2 2 20

2 1 10

....

3 1 12

3 2 18

3 3 14

...

...

Please help me..

[Matt J]

I see no difference between the data before and the data after (apart from order).

[Image Analyst]

The middle group has the second column flipped. But that's not enough to figure out what needs to be done in general. And what does this have to do with Image Processing, like the tag says?

[George]

i tag this question with ''image processing'' because these data come from grayscale image. What i want to do on my matrix is when the first column has an odd number the second and third column stay the same, when i have an even number the second and the third column reverse in order from bottom to top.

Answer 1

[Andrei Bobrov]

a - your array

a1 = a;
n = unique(a(:,1));
for jj = 1:numel(n)
    if rem(n(jj),2) == 0
        t = a1(:,1) == n(jj); 
        a1(t,:) = flipud(a1(t,:));
    end
end

[George]

Thank you Andrei!!!

Answer 2

[Evan]

M(:,:,2) = flipud(M(:,:,2))

As an example:

M = rand(3,3,3); %random example 3d matrix
M(:,:,2) = flipud(M(:,:,2));

[Evan]

In light of George's update in the below comment, this code does not do what he is asking for. http://www.mathworks.com/matlabcentral/answers/79846#comment_156778

Answer 3

[George]

i write this matrix to a .txt file and i would like to numerate the lines, for example :

1 1 1 6

2 1 2 8

3 1 3 15

....

50 2 1 10

51 2 2 20

52 2 3 13

....

Please will someone help me?