# init(rowCount:columnCount:columnStarts:rowIndices:attributes:blockSize:) Creates a new structure that represents the sparsity structure of a sparse matrix. ``` init(rowCount: Int32, columnCount: Int32, columnStarts: UnsafeMutablePointer, rowIndices: UnsafeMutablePointer, attributes: SparseAttributes_t, blockSize: UInt8) ``` ## Parameters `rowCount` The number of rows in the matrix. `columnCount` The number of columns in the matrix. `columnStarts` An array that specifies where each column starts in the row indices array. This array requires an additional, final entry that defines the final column’s length. `rowIndices` The row indices of the matrix. `attributes` The attributes of the matrix, such as whether it’s symmetrical or triangular. `blockSize` The block size of the matrix. ## Discussion --- 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)