---
title: nvec
framework: accelerate
role: symbol
role_heading: Instance Property
path: accelerate/sparsegmresoptions/nvec
---

# nvec

The number of orthogonal vectors the operation maintains.

## Declaration

```swift
var nvec: Int32
```

## Discussion

Discussion For GMRES and FGMRES variants, this is the number of iterations between restarts. For DQGMRES it’s the number of historical vectors the operation maintains in memory. If nvec is less than or equal to 0, the operation uses the default value of 16.

## See Also

### Inspecting GMRES Options

- [atol](accelerate/sparsegmresoptions/atol.md)
- [maxIterations](accelerate/sparsegmresoptions/maxiterations.md)
- [reportError](accelerate/sparsegmresoptions/reporterror.md)
- [reportStatus](accelerate/sparsegmresoptions/reportstatus.md)
- [rtol](accelerate/sparsegmresoptions/rtol.md)
- [variant](accelerate/sparsegmresoptions/variant.md)
- [SparseGMRESVariant_t](accelerate/sparsegmresvariant_t.md)