Increment loop index based on a condition

I have an array that has 100000+ values. every 3000th sample to a new array based on a condition.

1. I should compare every 3000th value and see if it differs from the previous 3000th sample by greater than 10. If so, I should add the sample, sample+100th element, sample+200th element to my new array.

2. If not, I should only add the 3000th sample element to my new array and then move to the next 3000th sample.

I have implemented this as an if-else loop inside a for loop. My problem is I am unable to increment the loop index if I first enter the if-loop and then go to the else loop next. I have tried using a while loop instead;however, the while loop executes forever and I don't get any output.

Any help is appreciated.

Thanks.

Answer 1

[Walter Roberson]

output = [];
for K = 6000 : 3000 : length(YourVector)
  if abs(YourVector(K) - YourVector(K-3000)) > 10
     output = [output, YourVector(K+[0 100 200])];
  else
     output = [output, YourVector(K)];
  end
end

[A VP]

Thank you. This helped me solve the problem!

Answer 2

[A VP]

Now I have an added condition to this problem : 1. I should compare every 3000th value and see if it differs from the previous 3000th sample by greater than 10. If so, I should add the sample, sample+100th element, sample+200th element, sample+300th element, sample+400th element, sample+500th element to my new array.

If one of the (sample+100th element, sample+200th element, sample+300th element, sample+400th element, sample+500th element) in the same order are different from any of the previous samples by 10, then I have to add the next 5 samples to the array. For eg : if (sample+300)-(sample+100)>10, then the new array becomes [output, sample+100, sample+200, sample+300,sample+400,sample+500,sample+600,sample+700,sample+800];

eg2 : if ((sample+500)-(sample+200)>10), then the new array becomes [output, sample+100, sample+200, sample+300, sample+400,sample+500,sample+600,sample+700,sample+800,sample+900,sample+1000];

This should continue inside a loop.

What I have now is this :

for i = 6000 : 3000 : length(YourVector)
      if abs(YourVector(i) - YourVector(i-3000)) > 10
         output = [output, YourVector(i+[0 100 200 300 400 500])];
         if abs(YourVector(i+100) - YourVector(i+500)) > 10
              output = [output, YourVector(i+[0 600 700 800 900 1000])];  
         end
       else
              output = [output, YourVector(i)];
      end

I am only able to compare the extreme elements for this, not any of the intermediate elements. Any help is appreciated.

Thank you.