Sorting out data in a matrix

For example, I have a 100 x 3 matrix A

A = [1 0 542

1 5 21

1 10 125

1 15 6245

1 20 2678

1 50 580

1 55 1205

1 60 196

2 0 5129

2 5 34

2 10 248

2 15 348

2 20 583

2 25 480

… … ...]

where, column 1 is object

column 2 is movement number

column 3 is the point of the object

Movement is determined by the spacing of the values in column 2, if the spacing is more than 5 it will be categorized as a new move. When lookin at the second column, starting at 0, 5, 10, 15 up to 20 all has a space of 5 and is considered to be 1 movement. The space between 20 and 50 is not 5, so 50 is not included in that movement and will be recorded as the start of a new movement. So for 1 movement of ID 1, the starting point is at 0 and the ending point is at 15. For movement 2 of ID 1, starting point is 580 and end point is 196. I want to determine how many movements each object ID has done. Also, the data in the 3rd column needs to be recorded at the start and end of a move.

The output matrix should look like this:

B = [1 1 542 2678

1 2 580 196

2 1 5129 480]

where, column 1 is object ID

column 2 is movement number

column 3 is starting point of movement

column 4 is endpoint of movement

[Rik]

Why did you edit away large parts of your question? I will restore it from Google cache. Removing your question like this is extremely rude.

If something isn't working, post a comment.

Answer 1

[Rik]

Loop through the elements of find(diff(A(:,3))>=5)

That way you can get the row indices for the cases you need. That should make it easy to create B.