# How to find a series of 'next max' and their indices in an array of numbers?

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Alon Rozen on 4 Sep 2019
Commented: Alon Rozen on 4 Sep 2019
Hi,
Suppose I have an array of numbers.
I want to find all the numbers, and their indices, which are largest then all previous ones.
For example, for the array:
X = [ 1 2 5 3 4 7 2 3 10 3]
I will get:
Largest: [1 2 5 7 10]
Indices: [1 2 3 6 9]
Sure I can solve it with a 'for' loop.
What will be the fastest way to do it in Matlab?

Fabio Freschi on 4 Sep 2019
Note that it should be
Largest = [1 2 5 7 10]
Alon Rozen on 4 Sep 2019
Thanks :)
Corrected.

Fabio Freschi on 4 Sep 2019
Edited: Fabio Freschi on 4 Sep 2019
use cummax to find the cumulative maximum, then play with the solution using unique
>> Y = cummax(X)
Y =
1 2 5 5 5 7 7 7 10 10
>> [largest,index] = unique(Y)
largest =
1 2 5 7 10
index =
1
2
3
6
9

#### 1 Comment

Alon Rozen on 4 Sep 2019
Great :)
Thanks!

R2016b

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