# init(device:transposeLeft:transposeRight:resultRows:resultColumns:interiorColumns:alpha:beta:) Initializes a matrix multiplication kernel. ``` init(device: any MTLDevice, transposeLeft: Bool, transposeRight: Bool, resultRows: Int, resultColumns: Int, interiorColumns: Int, alpha: Double, beta: Double) ``` ## Parameters `device` The device on which the matrix multiplication kernel will run. `transposeLeft` A boolean value that indicates if the left input matrix should be used in its transposed form. If the value is , then `op(A) = A**T`; otherwise, `op(A) = A`. `transposeRight` A boolean value that indicates if the right input matrix should be used in its transposed form. If the value is , then `op(B) = B**T`; otherwise, `op(B) = B`. `resultRows` The number of rows in the result matrix (`M` in the *BLAS GEMM* description). `resultColumns` The number of columns in the result matrix (`N` in the *BLAS GEMM* description). `interiorColumns` The number of columns of the left input matrix after the appropriate transpose operation has been applied (`K` in the *BLAS GEMM* description). `alpha` The scale factor to apply to the product, specified in `double` precision. This value will be converted to the appropriate precision in the implementation itself, subject to rounding and/or clamping as necessary. `beta` The scale factor to apply to the initial values of `C`, specified in `double` precision. This value will be converted to the appropriate precision in the implementation itself, subject to rounding and/or clamping as necessary. ## Return Value A valid [`MPSMatrixMultiplication`](/documentation/MetalPerformanceShaders/MPSMatrixMultiplication) object or `nil`, if failure. --- 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)