The sequence of actions in a vector (football match)

Hi everyone,

I am a Sports Science student, and I am starting to use Matlab.

I analysed a football match, and in an excel' column I put the sequence of actions that a team made:

"Player1

Player2

Player 11

Player1

shoot"

"Player1

Player2

Player 11

Player1

missed pass"

In the example, I represented two ball possessions, the first ends with a "shoot" and the second one end with a "missed pass". According to the example, I would like to represent the number of ball possessions of that team in another column:

1

1

1

1

1

2

2

2

2

2

How can I do that?

P.S. When two players appear in a row, there was a pass between them. Furthermore, I already changed the name of the players per numbers, as well as the technical actions (shoot, missed pass, etc...).

Regards,

[Guillaume]

Well, that's fairly easy to do. However, to show you code we need to know:

• how is the data actually stored in matlab?
• What are the actual terms that trigger the change of possession. It seems that 'shoot' and 'missed pass' are two of them, any other or a pattern to use?

[Aragorn23]

Hi Guillaume,

First of all, thank you for your response.

The data was all stored in an excel' column (first column).

A ball possession changes, when a team made a shoot (50), missed a pass (51), the opposite team steal/intercept the ball (52), the opposite team made a foul (53), the team throw the ball away (54).

[Guillaume]

So you haven't imported the data in matlab yet and you need help with that as well? If so, attach an example excel file.

In order to detect the change of possession we're going to have to do some string comparison, so we need to know the exact terms to search for (and whether case should be ignored or not) or the exact pattern to search for.

What is the significance of the numbers 50 to 54 you've given?

[Aragorn23]

I already imported the data to matlab.

These are the first four ball possesions

9

10

6

7

8

11

10

51 (pass missed)

6

3

4

5

11

9

50 (shoot)

8

4

10

53 (oppsoite team foul)

1

2

6

7

10

9

11

54 (team throw the ball away)

[Guillaume]

So, you've got a column vector of numbers?

And the change of possession is whenever there's any number >= 50?

[Aragorn23]

Exactly.

Answer 1

[Guillaume]

No idea how we went from your original question to a vector of numbers. Anyway, if I understood correctly:

%example data
match = [9; 10; 6; 7; 8; 11; 10; 51; 4; 5; 11; 9; 50; 8; 4; 10; 53; 1; 2; 6; 7; 10; 9; 11; 54]

%not entirely clear on the desired output
%either
possession1 = cumsum([1; match(1:end-1)>=50])
%or
possession2 = mod(cumsum([0; match(1:end-1)>=50]), 2) + 1

%for visualisation of the results:
table(match, possession1, possession2)

[Aragorn23]

The "possession1" solved my problem, thanks for your help.

One last question.

I have the same vector. But this time, I want the numbers above "50" are considered as the beginning of the new ball possession.

How can I do that?

[Guillaume]

It's even simpler:

possession = cumsum(match >= 50) + 1

[Aragorn23]

It worked. Thank you again