Function

cblas_srotg(_:_:_:_:)

Constructs a Givens rotation matrix.

Declaration

Parameters

a

Single-precision value a. Overwritten on return with result r.

b

Single-precision value b. Overwritten on return with result z (zero).

c

Unused on entry. Overwritten on return with the value cos(θ).

s

Unused on entry. Overwritten on return with the value sin(θ).

Discussion

Given a vertical matrix containing a and b, computes the values of cos θ and sin θ that zero the lower value (b). Returns the value of sin θ in s, the value of cos θ in c, and the upper value (r) in a.

See Also

Single-Precision Float Matrix Functions

func cblas_sasum(Int32, UnsafePointer<Float>!, Int32) -> Float

Computes the sum of the absolute values of elements in a vector (single-precision).

func cblas_saxpy(Int32, Float, UnsafePointer<Float>!, Int32, UnsafeMutablePointer<Float>!, Int32)

Computes a constant times a vector plus a vector (single-precision).

func cblas_snrm2(Int32, UnsafePointer<Float>!, Int32) -> Float

Computes the L2 norm (Euclidian length) of a vector (single precision).

func cblas_sscal(Int32, Float, UnsafeMutablePointer<Float>!, Int32)

Multiplies each element of a vector by a constant (single-precision).

func cblas_sspmv(CBLAS_ORDER, CBLAS_UPLO, Int32, Float, UnsafePointer<Float>!, UnsafePointer<Float>!, Int32, Float, UnsafeMutablePointer<Float>!, Int32)

Scales a packed symmetric matrix, then multiplies by a vector, then scales and adds another vector (single precision).

func cblas_sspr(CBLAS_ORDER, CBLAS_UPLO, Int32, Float, UnsafePointer<Float>!, Int32, UnsafeMutablePointer<Float>!)

Rank one update: adds a packed symmetric matrix to the product of a scaling factor, a vector, and its transpose (single precision).

func cblas_ssymv(CBLAS_ORDER, CBLAS_UPLO, Int32, Float, UnsafePointer<Float>!, Int32, UnsafePointer<Float>!, Int32, Float, UnsafeMutablePointer<Float>!, Int32)

Scales a symmetric matrix, multiplies by a vector, then scales and adds another vector (single precision).

func cblas_ssyr(CBLAS_ORDER, CBLAS_UPLO, Int32, Float, UnsafePointer<Float>!, Int32, UnsafeMutablePointer<Float>!, Int32)

Rank one update: adds a symmetric matrix to the product of a scaling factor, a vector, and its transpose (single precision).

func cblas_ssyrk(CBLAS_ORDER, CBLAS_UPLO, CBLAS_TRANSPOSE, Int32, Int32, Float, UnsafePointer<Float>!, Int32, Float, UnsafeMutablePointer<Float>!, Int32)

Rank-k update—multiplies a symmetric matrix by its transpose and adds a second matrix (single precision).