Function

sparse_vector_norm_double(_:_:_:_:)

Computes the specified norm of the double-precision sparse vector x.

Declaration

func sparse_vector_norm_double(_ nz: sparse_dimension, _ x: UnsafePointer<Double>!, _ indx: UnsafePointer<sparse_index>!, _ norm: sparse_norm) -> Double

Parameters

nz

The number of nonzero values in the sparse vector x.

x

Pointer to the dense storage for the values of the sparse vector x. The corresponding entry in indx holds the index of the value. Contains nz values.

indx

Pointer to the dense storage for the index values of the sparse vector x. The corresponding entry in x holds the values of the vector. Contains nz values.

norm

The norm to be computed. Must be one of SPARSE_NORM_ONE, SPARSE_NORM_TWO, or SPARSE_NORM_INF. See discussion for further details.

Return Value

The requested norm.

Discussion

Compute the specified norm of the sparse vector x. Specify one of:

SPARSE_NORM_ONE

sumᵢ ( | x[i] | )

SPARSE_NORM_TWO

sqrt ( sumᵢ (x[i])² )

SPARSE_NORM_INF

maxᵢ( | x[i] | )

SPARSE_NORM_R1

Not supported, undefined.

If norm is not one of the enumerated norm types, the default value is SPARSE_NORM_INF.

Indices in indx are always assumed to be stored in ascending order. Additionally, indices are assumed to be unique. The behavior of this function is undefined if either of these assumptions are not met.

All indices are 0 based (the first element of a pointer is ptr[0]).

See Also

Vector-Vector Operations

func sparse_inner_product_dense_double(sparse_dimension, UnsafePointer<Double>!, UnsafePointer<sparse_index>!, UnsafePointer<Double>!, sparse_stride) -> Double

Computes the inner product of sparse vector x with double-precision y, with both vectors containing double-precision values.

func sparse_inner_product_dense_float(sparse_dimension, UnsafePointer<Float>!, UnsafePointer<sparse_index>!, UnsafePointer<Float>!, sparse_stride) -> Float

Computes the inner product of sparse vector x with dense vector y, with both vectors containing single-precision values.

func sparse_vector_add_with_scale_dense_double(sparse_dimension, Double, UnsafePointer<Double>!, UnsafePointer<sparse_index>!, UnsafeMutablePointer<Double>!, sparse_stride)

Scales the sparse vector x by alpha and adds the result to the dense vector y, with both vectors containing double-precision values.

func sparse_vector_add_with_scale_dense_float(sparse_dimension, Float, UnsafePointer<Float>!, UnsafePointer<sparse_index>!, UnsafeMutablePointer<Float>!, sparse_stride)

Scales the sparse vector x by alpha and adds the result to the dense vector y, with both vectors containing single-precision values.