## How to group a matrix based on height

### R MONTGOMERY (view profile)

on 17 Mar 2019
Latest activity Answered by Akira Agata

### Akira Agata (view profile)

on 8 Apr 2019
EDIT __________
my apolgies for confusion
Say I have a matrix of nx1 as such:
[..... 2.59, 2.6, 2.6, 1.7 , ....... , 1.8 , 2.57 , 2.6, 2.7, 1.8.....]
(block 1) (block 2)
Is there a function that groups that first "block" of values over 2.5 as "block 1" and then the second "block" of values over 2.5 as another thing such as "block 2"
my apologies I appreciate your help

Walter Roberson

### Walter Roberson (view profile)

on 17 Mar 2019
There are no locations in your sample data where the difference in heights between two columns exceeds 2.5 ("values above 2.5 above/below each other") ?
Image Analyst

### Image Analyst (view profile)

on 17 Mar 2019
We're not going to type that in. Please attach the data with the paperclip icon. Make it easy for people to help you, not hard.
R MONTGOMERY

### R MONTGOMERY (view profile)

on 17 Mar 2019
Im sorry Im not very clear.
Let me ask this instead as my english skills are not so great.
Say I have a matrix of nx1 as such:
[..... 2.59, 2.6, 2.6, 1.9 , ....... , 1.9 , 2.57 , 2.6......]
Is there a function that groups that first "block" of values over 2.5 as "block 1" and then the second "block" of values over 2.5 as another thing such as "block 2"
my apologees I appreciate your help

R2018a

### Akira Agata (view profile)

on 8 Apr 2019

If you have Image Processing Toolbox, you can do this task easier by using bwlabel function. The following is a simple example.
nx1 = [1.1, 2.59, 2.6, 2.6, 1.7, 1.8, 2.57, 2.6, 2.7, 1.8];
idx = nx1 > 2.5;
group = bwlabel(idx);
The result is like:
>> group
group =
0 1 1 1 0 0 2 2 2 0