# Documentation

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# Measurements and Statistics

Bistate waveform measurements, variance, histogram, autocorrelation

You can use DSP System Toolbox™ blocks and System objects to measure the moving statistics and stationary statistics of signals in MATLAB® and Simulink®. Moving statistics refer to the statistics of streaming signals that change with time. In the sliding window method for computing moving statistics, a window of specified length moves over the data sample by sample as the new data comes in. The objects and blocks compute the statistics of the data within this window. The exponential weighting method applies a set of weights to the data samples and processes the weighted data. These weights are computed recursively based on the age of the data. For stationary statistics, the blocks and objects compute the statistics of all the data that is available in a batch.

In addition to measuring statistics, you can also measure the histogram, pulse metrics, and transition metrics of signals by using the `dsp.Histogram`, `dsp.PulseMetrics`, and `dsp.TransitionMetrics` System objects.

## System Objects

 `dsp.MedianFilter` Median filter `dsp.MovingAverage` Moving average `dsp.MovingMaximum` Moving maximum `dsp.MovingMinimum` Moving minimum `dsp.MovingRMS` Moving Root Mean Square `dsp.MovingStandardDeviation` Moving standard deviation `dsp.MovingVariance` Moving variance
 `dsp.Autocorrelator` Autocorrelation sequence `dsp.Crosscorrelator` Cross-correlation of two inputs `dsp.Maximum` Find maximum value of input or sequence of inputs `dsp.Mean` Find mean value of input or sequence of inputs `dsp.Median` Median value of input `dsp.Minimum` Find minimum values of input or sequence of inputs `dsp.RMS` Root mean square of vector elements `dsp.StandardDeviation` Standard deviation of input or sequence of inputs `dsp.Variance` Variance of input or sequence of inputs
 `dsp.Histogram` Histogram of input or sequence of inputs `dsp.PeakToPeak` Peak-to-peak value `dsp.PeakToRMS` Peak-to-root-mean-square value of vector `dsp.PulseMetrics` Pulse metrics of bilevel waveforms `dsp.StateLevels` State-level estimation for bilevel rectangular waveform `dsp.TransitionMetrics` Transition metrics of bilevel waveforms

## Blocks

 Median Filter Median filter Moving Average Moving average Moving Maximum Moving maximum Moving Minimum Moving minimum Moving RMS Moving RMS Moving Standard Deviation Moving standard deviation Moving Variance Moving variance
 Autocorrelation Autocorrelation of N-D array Correlation Cross-correlation of two N-D arrays Maximum Maximum values of input or sequence of inputs Mean Find mean value of input or sequence of inputs Median Median value of input Minimum Minimum values of input or sequence of inputs RMS Root mean square value of input or sequence of inputs Sort Sort input elements by value Standard Deviation Standard deviation of input or sequence of inputs Variance Variance of input or sequence of inputs
 Histogram Histogram of input or sequence of inputs

## Concepts

What Are Moving Statistics?

Learn how moving statistics are calculated.

Sliding Window Method and Exponential Weighting Method

Learn the differences between the sliding window method and exponential weighting method.

How Is a Moving Average Filter Different from an FIR Filter?

Moving average filter is a special case of the FIR filter.

Signal Statistics

This example shows how to perform statistical measurements on an input data stream using DSP System Toolbox™ functionality available at the MATLAB® command line.

Measure Statistics of Streaming Signals

Compute the moving average of streaming signals using MATLAB functions and System objects.

Remove High-Frequency Noise from Gyroscope Data

Remove high-frequency noise using a median filter.

Energy Detection in the Time Domain

Detect the event when the signal energy crosses a particular threshold value.

Measure Pulse and Transition Characteristics of Streaming Signals

Learn how to compute the basic pulse and transition metrics of streaming signals.

Variable-Size Signal Support DSP System Objects

List of System objects which support variable-sized signals in DSP System Toolbox.