Sum values for a spreedsheet of excel

Hello, i want to do this:

1. load a excel spreedsheet
2. read that excel spreedsheet
3. set a stepsize of 4 numbers
4. sum from 4 by 4 the elements of the column vector
5. generate a new column vector only with the the new values (for instance if at the begining i had 8 values now i should has only 2 values)

this was the code that i did for it,

k = 1;
stepsize = 4;
xlsread('DatosCM.xlsx', 1, 'c2:c10');
for nn = 2:stepsize:10-stepsize
    partsum(k) = sum(vekt(nn:nn+stepsize-1));
    k = k+1;
end

that code send me this error Index exceeds matrix dimensions.

Error in consumo2 (line 7) partsum(k) = sum(vekt(nn:nn+stepsize-1));

[Adam]

Surely you need to assign the output of xlsread to a variable?

Answer 1

[Image Analyst]

Try

vekt = xlsread(............

[Tony Castillo]

Thanks so much, is correct your solution.