Sum of rows in a defined rhythm

Hello everyone,

i have the following array:

A(1:5*270,1)=1;

Now i would like to calculate the sum of every 270th Element. The new array is B. Every element will have the value 5 (1+1+1+1+1). Can someone tell me how i can do that?

The numbers are examples of course. In the original data there is one column with height of 5*270 and after 270 rows the numbers change.

[Alex Mcaulley]

Do you mean

sum(A(270:270:end,1))

[Max Bornemann]

Thank you for your fast answer, sir!

No, the solution array shall be:

B(1:270,1)=5;

With your solution the ans is 5.

I want

5

5

5

5

....

x270

[Alex Mcaulley]

What's wrong with this?

A(1:5*270,1)=1;
B(1:270,1) = sum(A(270:270:end,1)) 

[Max Bornemann]

There is nothing wrong, i didn´t get it :D

I just tried B = sum(A(270:270:end,1))

Thank you!

[Max Bornemann]

Somehow i cant accept your answer, i think it is just a comment. Maybe you can write it as an answer.

[Alex Mcaulley]

Moved to answers :)

Answer 1

[Alex Mcaulley]

A(1:5*270,1)=1;
B(1:270,1) = sum(A(270:270:end,1)) 

[Max Bornemann]

I have a further question:

I have the following code:

A(1:5*270,1)=1;
A(2,1)=5; % should result in a different value in row 2 in the calculation

The following calculation has the result i want:

B(1:270) = 1+exp(A(1:270))+exp(A(271:540))+exp(A(541:810))+exp(A(811:1080))+exp(A(811:1080))+exp(A(1081:1350));

I am searching for a way to simplify this calculation with help of a sum. I tried to apply your approach, but somehow it doesn´t work (every row has the same value, instead the second should have a different value like above).

B(1:270) = 1+sum(exp(A(270:270:end)));

[Max Bornemann]

I found a solution :-)

B=1+sum(exp(reshape(A,270,5)),2);