# vSgemv(_:_:_:_:_:_:_:_:) Multiplies a vector by a scalar. Multiplies a matrix by another scalar, then by a second vector, and adds the resulting vector to the first vector. This function can also perform the calculation with the transpose of the original matrix instead of the matrix itself. A selector parameter determines whether the transpose is used. ``` func vSgemv(_ forma: CChar, _ m: Int32, _ n: Int32, _ alpha: Float, _ a: UnsafePointer, _ x: UnsafePointer, _ beta: Float, _ y: UnsafeMutablePointer) ``` ## Parameters `forma` selects the variant computation to be performed: ‘T’ causes the transpose of matrix `a` to be used, ‘N’ causes `a` itself to be used. `m` number of rows in `a`. If `forma` = ‘N’, `m` is the length of vector `y`; if `forma` = ‘T’, `m` is the length of vector `x`; must be a multiple of 4. `n` number of columns in `a`. If `forma` = ‘N’, `m` is the length of vector `x`; if `forma` = ‘T’, `m` is the length of vector `y`; must be a multiple of 4. `alpha` scalar multiplier for matrix `a`. `a` `m` by `n` matrix with elements of type `float`. `x` vector with elements of type `float`. `beta` scalar multiplier for vector `y`. `y` destination vector with `n` elements of type `float`. ## Discussion Vector `y` is multiplied by `beta`. Matrix `a` is multiplied by `alpha`. Then if `forma` = ‘N’, `a` is multiplied by vector `x`; if `forma` = ‘T’, the transpose of `a` is multiplied by `x`. The resulting vector is added to vector `y`, and the results are stored in `y`. --- 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)