How to set the boundaries?

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Ra Ga
Ra Ga on 18 Mar 2018
Commented: Ra Ga on 18 Mar 2018
Hello,
Please help me :)
I have a row with 0 and 1 (they are used for classification) and its indexes. I need to get just the boundaries for the interval of 0 or 1. How I can do it?
For example this is what I have:
targets=[0 0 0 1 1 1 0 0 1 1 0 0 0]
index= [0 1 2 3 4 5 6 7 8 9 10 11 12]
This is what I want to get:
targ= [0 1 0 1 0]
boundindex=[0 3 6 8 12]
Thanks!

Accepted Answer

Image Analyst
Image Analyst on 18 Mar 2018
Try this:
boundindex = [0, find(abs(diff(targets)))]
The only difference is that my array gives 10 as the final value, because 10 is where the final group of 0's starts. Not sure how you got 12. Why do you want 12 and how did you arrive at that value?
Not sure what the point of targ is or why it's needed so I didn't compute it.
  4 Comments
Ra Ga
Ra Ga on 18 Mar 2018
Edited: Image Analyst on 18 Mar 2018
I have this:
targets=[0 0 0 1 1 1 0 0 1 1 0 0 0] % describe peaks
index= [0 15 20 35 45 50 60 75 80 99 101 111 120] % index of the peak
I have the row of peaks (PPG signal). 0 - one class, 1 - another class.
What I want to get just bound of the classes, not for each peak. Lets say that first three peaks belong to 0 class and other three to 1 class. So, I want to remove middle values.
This is what I want to get:
targ= [0 1 0 1 0]
index= [0 35 60 80 101]
Image Analyst
Image Analyst on 18 Mar 2018
Try this:
targets=[0 0 0 1 1 1 0 0 1 1 0 0 0] % describe peaks
index= [0 15 20 35 45 50 60 75 80 99 101 111 120] % index of the peak
startingIndexes = [0, find(abs(diff(targets)))]
boundindex = index(startingIndexes+1)
targ = targets(startingIndexes+1)
Shows in command window:
boundindex =
0 35 60 80 101
targ =
0 1 0 1 0
just as you requested.
Also read this how to format your code so I don't have to keep fixing your code formatting.

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More Answers (1)

Ra Ga
Ra Ga on 18 Mar 2018
There were some mistakes in my second answer. I need some help to the last question.
  2 Comments
Image Analyst
Image Analyst on 18 Mar 2018
I don't know what to do. What is your "second answer"?
Why is the code I gave in my last comment not what you want? It gave what you said you wanted.
Ra Ga
Ra Ga on 18 Mar 2018
I see your answer at the moment. Previous it looks different. Thank you. It helped me!

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