# Descriptive Statistics

Use `findpeaks`

to locate the local maxima of a signal and sort the
peaks by height, width, or prominence. Determine the crest factor of a signal using the
`peak2rms`

function and compute common descriptive statistics like maxima,
minima, standard deviations, and RMS levels. Search for signals of interest in larger data
sets and align signals in time. Locate points where a signal changes abruptly or drifts
beyond a target range. Label signals for analysis or machine and deep learning
applications.

## Apps

Signal Analyzer | Visualize and compare multiple signals and spectra |

Signal Labeler | Label signal attributes, regions, and points of interest, and extract
features (Since R2019a) |

## Functions

## Topics

**RMS Value of Periodic Waveforms**Find the root mean square value of a sine wave, a square wave, and a rectangular pulse train.

**Find Peaks in Data**Locate the local maxima in a set of data and determine if those peaks occur periodically.

**Prominence**The

*prominence*of a peak measures how much the peak stands out due to its intrinsic height and its location relative to other peaks.**Human Activity Recognition Simulink Model for Smartphone Deployment (Statistics and Machine Learning Toolbox)**Generate code from a classification Simulink

^{®}model prepared for deployment to a smartphone.**Choose an App to Label Ground Truth Data**Decide which app to use to label ground truth data: Image Labeler, Video Labeler, Ground Truth Labeler, Lidar Labeler, Signal Labeler, or Medical Image Labeler.