---
title: "vvexpm1(_:_:_:)"
framework: accelerate
role: symbol
role_heading: Function
path: "accelerate/vvexpm1(_:_:_:)"
---

# vvexpm1(_:_:_:)

Calculates eˣ-1 for each element in an array of double-precision values.

## Declaration

```swift
func vvexpm1(_: UnsafeMutablePointer<Double>, _: UnsafePointer<Double>, _: UnsafePointer<Int32>)
```

## Discussion

Discussion Parameters: If x is nearly zero, the common expression exp(x)-1.0 will suffer from catastrophic cancellation and the result will have little or no precision.  This function provides an alternative means to do this calculation without the risk of significant loss of precision. This function provides high accuracy when x is around zero.

## See Also

### Array-Oriented Exponential and Logarithmic Functions

- [exp(_:)](accelerate/vforce/exp(_:)-76nrd.md)
- [exp(_:)](accelerate/vforce/exp(_:)-5iaun.md)
- [exp(_:result:)](accelerate/vforce/exp(_:result:)-34nxw.md)
- [exp(_:result:)](accelerate/vforce/exp(_:result:)-4k85n.md)
- [exp2(_:)](accelerate/vforce/exp2(_:)-2m5q.md)
- [exp2(_:)](accelerate/vforce/exp2(_:)-4mm9y.md)
- [exp2(_:result:)](accelerate/vforce/exp2(_:result:)-6ru6m.md)
- [exp2(_:result:)](accelerate/vforce/exp2(_:result:)-8m564.md)
- [expm1(_:)](accelerate/vforce/expm1(_:)-xkzx.md)
- [expm1(_:)](accelerate/vforce/expm1(_:)-mfq5.md)
- [expm1(_:result:)](accelerate/vforce/expm1(_:result:)-4dpl4.md)
- [expm1(_:result:)](accelerate/vforce/expm1(_:result:)-2yhs3.md)
- [log10(_:)](accelerate/vforce/log10(_:)-9wr68.md)
- [log(_:)](accelerate/vforce/log(_:)-2gh9a.md)
- [log(_:)](accelerate/vforce/log(_:)-5ffby.md)