# Moving Average (Variable Frequency)

Variable frequency moving average-value computation

• Library:
• Simscape / Electrical / Control / General Control

## Description

The Moving Average (Variable Frequency) block computes the moving average value of an input signal of variable frequency. Use this block to filter higher frequency signal components and to smooth noisy signals.

### Equations

The moving average is computed based on a moving time window. The moving average for continuous-time is calculated as

`$\overline{u}=\frac{1}{{T}_{0}}\underset{{t}_{0}}{\overset{{t}_{0}+{T}_{0}}{\int }}u\left(t\right)dt,$`

where:

• u(t) is the input signal.

• T0 is equal to $\frac{1}{f}$

• f is the fundamental frequency of the signal.

The moving average for discrete-time is calculated as:

`$\overline{u}\left(k\right)=\frac{1}{{T}_{0}}\sum _{i=0}^{n-1}u\left(k-i\right).$`

Note

If you use this block for continuous-time operations and set the Sample time (-1 for inherited) parameter to `0`, you should also specify the value of the Buffer size parameter to ensure it covers the moving time window.

### Assumptions and Limitations

The output is initialized with an initial condition in the time interval `[0, T0]`.

## Ports

### Input

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Moving average input, specified as a scalar or vector.

Data Types: `single` | `double`

Frequency, specified as a scalar or vector in Hz.

Data Types: `single` | `double`

### Output

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Moving average of the input signal, returned as a scalar or vector.

Data Types: `single` | `double`

## Parameters

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Initial frequency of the signal, in Hz. If you specify the initial frequency using a vector, it must match the dimensions of the input vector.

Minimum frequency of the signal, in Hz. If you specify the minimum frequency using a vector, it must match the dimensions of the input vector.

Initial value of the input signal.

Size of the buffer.

#### Dependencies

To enable this parameter, set Sample time (-1 for inherited) to `0`.

Time between consecutive block executions. During execution, the block produces outputs and, if appropriate, updates its internal state. For more information, see What Is Sample Time? and Specify Sample Time.

For inherited discrete-time operation, specify `-1`. For discrete-time operation, specify a positive integer. For continuous-time operation, specify `0`.

If this block is in a masked subsystem, or other variant subsystem that allows you to switch between continuous operation and discrete operation, promote the sample time parameter. Promoting the sample time parameter ensures correct switching between the continuous and discrete implementations of the block. For more information, see Promote Block Parameters on a Mask.

## Version History

Introduced in R2020a