How can I create a vector that shows the sum of the 60 values before each value of another vector?

If a have this vector --> x=[0:1:1000] how can i create a vector of length 1000 too.. that is: first value 0, second 0+1.. value #59 from 0 to 59 and when the value is greater than 60 it shows the sum of the 60 values before for example the entry 100 should be from 40 to 100 etc..

[Walter Roberson]

"60 values before" implies that 60 values are to be added. 40 to 100 is 61 values.

Answer 1

[Walter Roberson]

https://www.mathworks.com/help/matlab/ref/movsum.html

Or you can cumsum() and subtract the value 60-ish earlier in the cumsum

[Walter Roberson]

t = cumsum(zeros(1,60),x);
t(61:end) - t(1:end-60)

Answer 2

[Star Strider]

I’m not certain a vector is possible, but a matrix approach could be.

Consider the rows of ‘out’:

N =  5;                                             % RowLength (Use: 60)
L = 10;                                             % Vector Length (Use: 1000)
out = hankel(1:N, N:L);
out(2:end,:) = cumsum(out(2:end,:),2);

I used the example with a short vector to illustrate the approach. Experiment to get the result you want.

Answer 3

[Image Analyst]

Here's a way to do it in one line of code with conv().

out = conv(x, [zeros(1,59), ones(1,60)], 'same')

To prove it, here's a full demo where I compare that method to a simple intuitive for loop to prove that it's the same.

x=[0:1:1000] 

kernel = [zeros(1,59), ones(1,60)]
out = conv(x, kernel, 'same')

% Compare with for loop method:
for k = 1 : length(x)
  i2 = k;
  i1 = max(1, i2 - 59);
  outf(k) = sum(x(i1:i2));
end
diffs = outf - out
maxDiff = max(diffs)  % Should be 0