How do I create a vector of the average of consecutive elements of another vector (without using a loop)?

Say, I have a vector A=[2 4 6 8 10]. Is there any way I can create a vector of the average of consecutive elements of A, i.e. B=[3 5 7 9] without using a loop? Is there any matlab function to do that? Thanks in advance.

Answer 1

[Azzi Abdelmalek]

A=[2 4 6 8 10]
B=mean([A(1:end-1);A(2:end)])

[Rinu]

Thanks, that's a very simple way to do that.

[Sk Rafidul]

helpful. Thanks

Answer 2

[Jan]

This is simpler and occupies less temporary memory than Azzi's approach:

A = [2 4 6 8 10];
B = 0.5 * (A(1:end-1) + A(2:end))

[Rinu]

Thanks a lot.

Answer 3

[Matthew Crema]

One way:

A=[2 4 6 8 10];
foo = conv([1 1], A)/2;
B = foo(2:end-1)
B =

       3     5     7     9

-Matt

[Rinu]

Thanks.

[Jan]

Instead of dividing the array after the application of conv, you can divide the parameters instead: conv([0.5, 0.5], A) . The avoids the expensive division of all array elements.

[Matthew Crema]

Yup. But I agree that the use of indexing seems better with respect to readability and marginally better speed.

[Jan]

The speed argument might change, when the data exceed a certain size.

[Andrei Bobrov]

conv2(A,[.5 .5],'valid')