---
title: atol
framework: accelerate
role: symbol
role_heading: Instance Property
path: accelerate/sparsecgoptions/atol
---

# atol

The absolute convergence tolerance.

## Declaration

```swift
var atol: Double
```

## Discussion

Discussion ‖ b-Ax ‖₂ < * ‖ b-Ax₀ ‖₂ + atol indicates convergence.

## See Also

### Inspecting CG Options

- [maxIterations](accelerate/sparsecgoptions/maxiterations.md)
- [reportError](accelerate/sparsecgoptions/reporterror.md)
- [reportStatus](accelerate/sparsecgoptions/reportstatus.md)
- [rtol](accelerate/sparsecgoptions/rtol.md)