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sum every 24 rows in a vector

Asked by Andrew Alkiviades on 24 Sep 2012
Latest activity Commented on by Mohamed Atef on 19 Jan 2019
Hi I am trying to find an output which is the sum of every 24 rows of a 8760x1 vector below as hourly_deficit. Therefore I am trying to sum rows 1:24, 25:49, 50:73 etc etc
I am trying to do this on the line below
for idx_number_panels = 1:length(number_panels) % range of PV panel units examined
for idx_number_turbines = 1:length(number_turbines) % range of wind turbine units examined
for idx_number_batteries = 1:length(number_batteries) % range of battery units examined
for h=2:8759 %# hours
hourly_deficit(idx_number_panels,idx_number_turbines,idx_number_batteries, h) = hourly_annual_demand(h) - (hourly_annual_PV(h)*number_panels(idx_number_panels)) - (hourly_annual_WT(h)*number_turbines(idx_number_turbines));

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3 Answers

Answer by Login_Name
on 24 Sep 2012
Edited by Login_Name
on 24 Sep 2012
 Accepted Answer

If A is 8760-by-1, and you want to find the sum of every 24 elements, such that you will end up with 365 sums, then do:
sum(reshape(A,24,365))
As an example you can see easier, get the sum of every two elements of a 10-by-1:
A = (1:10)'
B = reshape(A,2,5)
sum(B)

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Thanks alot man

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Answer by Daniel Shub
on 24 Sep 2012
Edited by Daniel Shub
on 24 Sep 2012

I am not sure what all the code you posted has to do with anything ...
If I have a 8760x1 array
x = randn(8760, 1);
I can reshape it to be 24x365 with
y = reshape(x, 24, 365);
and then sum each of the 365 columns
z = sum(y);
EDIT
You could also filter the data
z = filter(ones(24, 1), 1, x);
z = z(24:24:end);

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Answer by Honglei Chen
on 24 Sep 2012
Edited by Honglei Chen
on 24 Sep 2012

Not sure what your end format is, but the following code adds every 24 rows and retain all the results in one column
reshape(sum(reshape(x,24,[])),[],1)

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