Every 2 rows (2x2 matrix) to perform determinant calculation

Hi all, can i know how to extract every two rows of my data to perform determinant calculation?

For example i have data:

1 2

3 4

5 6

7 8

9 10

11 12

so i want to select every two rows in order to perform determinant calculation, how can i do that? my final results should be:

-2

-2

-2

Regards,

Answer 1

[Matt J]

m=size(data,1);
i=1:2:m;
j=2:2:m; 

determinants = data(i,1).*data(j,2)-data(j,1).*data(i,2),

[cool dave]

Thx matt,

i would like to inquire another possible solutions for my problem.

for example if i have a set of data (10x1 matrix):

1

2

3

4

5

6

7

8

9

10

i want to extract every two rows to do multiplication with a 5x1 matrix:

1

2

3

4

5

how can i do that ? my final results should be:

1

2

6

8

15

18

28

32

45

50

i made attempt to acquire a solution using the code you suggested but i don't think i did it correctly.

r=[1;2;3;4;5];

m=size(data,1);

i=1:2:m; j=2:2:m;

n=[data(i) data(j)];

results=r.*n;

many thanks :)

[Matt J]

 results = bsxfun(@times,r,n);

or

 results = kron(r,[1;1]).*data

[cool dave]

it works perfectly. thank you so much mate :]

Answer 2

[Azzi Abdelmalek]

A=[1 2 ;3 4 ;5 6 ;7 8 ;9 10 ;11 12 ]
B=reshape(A',2,2,[])
out=arrayfun(@(x) det(B(:,:,x)),1:size(B,3))

Answer 3

[cool dave]

thank you so much of both of your responses, appreciate :)