Find Local Extrema
Find local maxima and minima in the Live Editor
Description
The Find Local Extrema task lets you interactively find local maxima and local minima in data. The task automatically generates MATLAB® code for your live script.
Using this task, you can:
Find local maxima, minima, or both in data from a workspace variable.
Adjust parameters to locate fewer or more extrema.
Visualize the detected extrema.
Open the Task
To add the Find Local Extrema task to a live script in the MATLAB Live Editor:
On the Live Editor tab, click Task and select the Find Local Extrema icon
.
In a code block in the live script, type a relevant keyword, such as
extrema
orfind
. SelectFind Local Extrema
from the suggested command completions.
Examples
Parameters
Input data
— Valid input data from workspace
vector | table | timetable
This task operates on input data contained in a vector, table, or timetable. The
data can be of type single
, double
,
logical
, or signed or unsigned integer types such as
int64
.
When providing a table or timetable for the input data, select All
supported variables
to operate on all variables with a supported type.
Select All numeric variables
to operate on all variables of
type single
or double
, or signed or unsigned
integer types. To choose specific supported variables to operate on, select
Specified variables
and then select the variables
individually.
Flat selection
— Flat region indicator
Center
(default) | First
| Last
| All
Specify a flat region indicator when you have local consecutive extrema values.
Method | Description |
---|---|
Center | Indicates only the center element of a flat region as the local extrema |
First | Indicates only the first element of a flat region as the local extrema |
Last | Indicates only the last element of a flat region as the local extrema |
All | Indicates all the elements of a flat region as the local extrema |
Min prominence
— Minimum prominence of extrema
0
(default) | positive scalar
Specify a minimum prominence to return only local extrema whose prominence is at least that value. Higher prominence values return fewer detected extrema.
The prominence of a local maximum (or peak) is a measure of how the peak stands out with respect to its height and location relative to other peaks. The prominence of a local minimum (or valley) is a measure of how the valley stands out with respect to its depth and location relative to other valleys.
Prominence window
— Window for computing prominence
Centered
(default) | Asymmetric
Specify a prominence window type and size to define a window of neighboring points for which to compute the prominence for each local extrema.
Window | Description |
---|---|
Centered | Specified window length centered about the current point |
Asymmetric | Specified window containing the number of elements before the current point and the number of elements after the current point |
Window sizes are relative to the X-axis variable units.