# Digital Signal Processing (DSP) filter

DSP (digital signal processing) filters are commonly used on input series to reduce their noise. This is typically a more rigorous option to "smooth" a series than using a [rolling aggregate](../card-rolling-aggregate/index.md).

Quiver includes three separate filtering algorithms/prototypes:

* [Butterworth ↗](https://en.wikipedia.org/wiki/Butterworth_filter)
* [Chebyshev ↗](https://en.wikipedia.org/wiki/Chebyshev_filter)
* [Inverse Chebyshev ↗](https://en.wikipedia.org/wiki/Chebyshev_filter).

For each algorithm, a filter response must be selected from the following options:

* [Lowpass ↗](https://en.wikipedia.org/wiki/Low-pass_filter)
* [Highpass ↗](https://en.wikipedia.org/wiki/High-pass_filter)
* [Bandpass ↗](https://en.wikipedia.org/wiki/Band-pass_filter)
* [Bandstop ↗](https://en.wikipedia.org/wiki/Band-stop_filter)

## Input type

Time series

## Output type

Time series

### Example

![DSP filter example](../../../assets/1aa3e6ba93b010e4c7db43dc4cce9dec43c506428971fdca90329c25ed8a9778.webp)

## Usage information

| Functionality | Availability |
| --- | --- |
| [Standard Quiver card](../core-concepts/index.md#cards) | Supported |
| [Transform table transform](../cards-transform-table/index.md) | Supported |