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# SparseMatrixStructure

A description of the sparsity structure of a sparse matrix.

```
struct SparseMatrixStructure
```

## Overview

The sparsity structure is in a *block compressed sparse column* format. The matrix consists of [`rowCount`](/documentation/Accelerate/SparseMatrixStructure/rowCount) x [`columnCount`](/documentation/Accelerate/SparseMatrixStructure/columnCount) blocks, each of which is a square matrix of some fixed size. The system stores this block size separately from the sparsity because the graph algorithms that operate on the structure don’t need it.

## Topics

### Creating a sparse matrix description

[`init(rowCount:columnCount:columnStarts:rowIndices:attributes:blockSize:)`](/documentation/Accelerate/SparseMatrixStructure/init(rowCount:columnCount:columnStarts:rowIndices:attributes:blockSize:))

Creates a new structure that represents the sparsity structure of a sparse matrix.

### Inspecting the properties of a sparse matrix description

[`attributes`](/documentation/Accelerate/SparseMatrixStructure/attributes)

The attributes of the matrix, such as whether it’s symmetrical or triangular.

[`blockSize`](/documentation/Accelerate/SparseMatrixStructure/blockSize)

The block size of the matrix.

[`columnCount`](/documentation/Accelerate/SparseMatrixStructure/columnCount)

The number of columns in the matrix.

[`columnStarts`](/documentation/Accelerate/SparseMatrixStructure/columnStarts)

The starting index for each column in the row indices array.

[`rowCount`](/documentation/Accelerate/SparseMatrixStructure/rowCount)

The number of rows in the matrix.

[`rowIndices`](/documentation/Accelerate/SparseMatrixStructure/rowIndices)

The row indices of the matrix.

## See Also

  <doc://com.apple.accelerate/documentation/Accelerate/creating-sparse-matrices>


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