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# nvec

The number of orthogonal vectors the operation maintains.

```
var nvec: Int32
```

## 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`](/documentation/Accelerate/SparseGMRESOptions/nvec) is less than or equal to `0`, the operation uses the default value of `16`.

---

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