# Descriptive Statistics

Peaks, RMS level, peak-to-peak amplitude, crest factor, dynamic time warping, CUSUM control chart, edit distance

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

## Functions

expand all

 `cummax` Cumulative maximum `cummin` Cumulative minimum `envelope` Signal envelope `max` Maximum elements of an array `mean` Average or mean value of array `meanfreq` Mean frequency `medfreq` Median frequency `median` Median value of array `min` Minimum elements of an array `movmad` Moving median absolute deviation `movmedian` Moving median `peak2peak` Maximum-to-minimum difference `peak2rms` Peak-magnitude-to-RMS ratio `rms` Root-mean-square level `rssq` Root-sum-of-squares level `seqperiod` Compute period of sequence `std` Standard deviation `var` Variance
 `alignsignals` Align two signals by delaying earliest signal `cusum` Detect small changes in mean using cumulative sum `dtw` Distance between signals using dynamic time warping `edr` Edit distance on real signals `findchangepts` Find abrupt changes in signal `finddelay` Estimate delay(s) between signals `findpeaks` Find local maxima `findsignal` Find signal location using similarity search `signalFrequencyFeatureExtractor` Streamline signal frequency feature extraction `signalTimeFeatureExtractor` Streamline signal time feature extraction `zerocrossrate` Zero-crossing rate
 `labeledSignalSet` Create labeled signal set `signalLabelDefinition` Create signal label definition `countlabels` Count number of unique labels `folders2labels` Get list of labels from folder names `splitlabels` Find indices to split labels according to specified proportions `signalMask` Modify and convert signal masks and extract signal regions of interest `binmask2sigroi` Convert binary mask to matrix of ROI limits `extendsigroi` Extend signal regions of interest to left and right `extractsigroi` Extract signal regions of interest `mergesigroi` Merge signal regions of interest `removesigroi` Remove signal regions of interest `shortensigroi` Shorten signal regions of interest from left and right `sigroi2binmask` Convert matrix of ROI limits to binary mask

## 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 Audio Labeler.