---
title: 1D correlation and convolution
framework: accelerate
role: collectionGroup
role_heading: API Collection
path: accelerate/1d-correlation-and-convolution
---

# 1D correlation and convolution

Use correlation to compare and convolution to combine vectors of real or complex data.

## Overview

Overview The vDSP library provides functions that calculate the convolution and correlation of a signal and a filter. Both operations compute the sliding dot product of the filter and the section of the input signal that the filter is over. What the operation produced depends on whether the stride is positive or negative: With a positive stride through the filter, the correlation operation computes the similarity between the signal and the filter. With a negative stride through the filter, the convolution operation computes the effect of the filter on the signal. For example, to apply a low-pass filter to a signal.

## Topics

### Real Vectors

- [convolve(_:withKernel:)](accelerate/vdsp/convolve(_:withkernel:)-1nv65.md)
- [convolve(_:withKernel:)](accelerate/vdsp/convolve(_:withkernel:)-4p0rt.md)
- [convolve(_:withKernel:result:)](accelerate/vdsp/convolve(_:withkernel:result:)-8j76l.md)
- [convolve(_:withKernel:result:)](accelerate/vdsp/convolve(_:withkernel:result:)-2z66w.md)
- [correlate(_:withKernel:)](accelerate/vdsp/correlate(_:withkernel:)-7f6o0.md)
- [correlate(_:withKernel:)](accelerate/vdsp/correlate(_:withkernel:)-9sol8.md)
- [correlate(_:withKernel:result:)](accelerate/vdsp/correlate(_:withkernel:result:)-1lb82.md)
- [correlate(_:withKernel:result:)](accelerate/vdsp/correlate(_:withkernel:result:)-377zj.md)

## See Also

### Vector and matrix correlation and convolution

- [2D convolution](accelerate/2d-convolution.md)