---
title: vDSP_biquad_SetupD
framework: accelerate
role: symbol
role_heading: Type Alias
path: accelerate/vdsp_biquad_setupd
---

# vDSP_biquad_SetupD

A data structure that contains precalculated data for use by the double-precision cascaded biquadratic IIR filter function.

## Declaration

```swift
typealias vDSP_biquad_SetupD = OpaquePointer
```

## See Also

### Creating a single-channel biquadratic filter setup

- [vDSP_biquad_Setup](accelerate/vdsp_biquad_setup.md)