performing certain operation from a set a certain set of values

i have dataset of 80 numbers=[1:1:80]

now i want to take first 8 values ,multiply each value by 2 and divide each by 2,so i will have 8 values each for multiplication and division,and then want to find average for that multilaction values and division values,same way i eant to perform for those 80 values from 1st 8,2nd 8,3rd 8........10th8 please help

Answer 1

[Andrei Caragea]

Mathematically speaking, you can compute the average on the initial set of values and then multiply it/ divide it by 2. If you want to do this in a nice "visual" way, you can do the following: A=[1:80]; B=reshape(A,8,10).'; 2*sum(B,2)*1/8 for the multiplication avg and 1/2*sum(B,2)*1/8 for the division. Reshape turns A into a 10 by 8 matrix( 10 rows of 8 values) as you suggest and then you can do the summation and the average.

[kash]

but Andrei a need for whole dataset,i need to use for loop.

[Walter Roberson]

You do not need a for loop to apply the techniques Andrei describes.