# init(reportError:variant:nvec:maxIterations:atol:rtol:reportStatus:) Returns a new GMRES options structure using the specified parameters. ``` init(reportError: ((UnsafePointer) -> Void)?, variant: SparseGMRESVariant_t, nvec: Int32, maxIterations: Int32, atol: Double, rtol: Double, reportStatus: ((UnsafePointer) -> Void)?) ``` ## Parameters `reportError` An optional error-reporting routine. `variant` The exact variant of GMRES to implement. `nvec` The number of orthogonal vectors the operation maintains. `maxIterations` The maximum number of iterations to perform. `atol` The absolute convergence tolerance. `rtol` The relative convergence tolerance. `reportStatus` The function to report status. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)