How to loop through array?

 function ans = stable(mass):
    for mass(k) in mass(:):
    average
  = mean(mass(k:k+1080);
       delta = abs(average - mass(k)) % I am totally lost
  as to how to make this loop over the entire array
       if (delta <= 0.0005*
  mean) = 1
          return mass(k+1080)
       else % bool = 0
          continue

So, I know this is a complete mess, but hear me out.

I want to build a function that takes in 'mass', which is an array of 10,000 numbers.

I want this to loop over the entire array:

Take first element of mass:

calculate mean of next 1080 elements

calculate delta = abs(mean - element)

if delta <= 0.0005 * mean, return True (1), return 1080 + 1st element (later, this would return 1080 + kth element)

I'm very new to Matlab. I'm only familiar with python which is what my code very vaguely resembles.

Please help.

[dpb]

Your description is very hazy...you say want to loop over full array, but only want the mean of array(2:1081). So what do you do with the rest of the array? Or do you mean you want a running average of 1080 elements? If the latter, do you want the length of the output array to be length(input)-1080 or length(input) or what?

How about an illustration with small sample size of say 10 or so elements in the array and 3 or 4 for 1080 and show us what you'd get for a sample dataset and how you'd calculate it on paper.

Answer 1

[Guillaume]

1. You really need to learn a modicum of matlab. The code you've posted is in no way valid matlab syntax

2. Do not use ans as a variable name. It's a special variable that matlab may modify.

3. Since R2016a, you can use movmean to calculate the moving average. Prior to that an easy way was to use a convolution. So, if I understood correctly

function [isstable, filteredmass] = stable(mass)
  runningmean = movmean(mass, 1080, 'Endpoints', 'discard');  %if r2016a or later
  %otherwise
  %runningmean = conv(mass, ones(1, 1080)/1080, 'valid');
  isstable = abs(mass(1:numel(runningmean)) - runningmean) < 0.0005 * runningmean;
  filteredmass = mass(1080:end);
  filteredmass = filteredmass(isstable); %I think this may be what you meant  
end