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Package blas32

v0.7.0
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The latest major version is .

Published: Feb 26, 2020 | License: BSD-3-Clause | Module: gonum.org/v1/gonum

Overview

Package blas32 provides a simple interface to the float32 BLAS API.

Index

func Asum

func Asum(x Vector) float32

Asum computes the sum of the absolute values of the elements of x:

\sum_i |x[i]|.

Asum will panic if the vector increment is negative.

func Axpy

func Axpy(alpha float32, x, y Vector)

Axpy adds x scaled by alpha to y:

y[i] += alpha*x[i] for all i.

Axpy will panic if the lengths of x and y do not match.

func Copy

func Copy(x, y Vector)

Copy copies the elements of x into the elements of y:

y[i] = x[i] for all i.

Copy will panic if the lengths of x and y do not match.

func DDot

func DDot(x, y Vector) float64

DDot computes the dot product of the two vectors:

\sum_i x[i]*y[i].

DDot will panic if the lengths of x and y do not match.

func Dot

func Dot(x, y Vector) float32

Dot computes the dot product of the two vectors:

\sum_i x[i]*y[i].

Dot will panic if the lengths of x and y do not match.

func Gbmv

func Gbmv(t blas.Transpose, alpha float32, a Band, x Vector, beta float32, y Vector)

Gbmv computes

y = alpha * A * x + beta * y   if t == blas.NoTrans,
y = alpha * Aᵀ * x + beta * y  if t == blas.Trans or blas.ConjTrans,

where A is an m×n band matrix, x and y are vectors, and alpha and beta are scalars.

func Gemm

func Gemm(tA, tB blas.Transpose, alpha float32, a, b General, beta float32, c General)

Gemm computes

C = alpha * A * B + beta * C,

where A, B, and C are dense matrices, and alpha and beta are scalars. tA and tB specify whether A or B are transposed.

func Gemv

func Gemv(t blas.Transpose, alpha float32, a General, x Vector, beta float32, y Vector)

Gemv computes

y = alpha * A * x + beta * y   if t == blas.NoTrans,
y = alpha * Aᵀ * x + beta * y  if t == blas.Trans or blas.ConjTrans,

where A is an m×n dense matrix, x and y are vectors, and alpha and beta are scalars.

func Ger

func Ger(alpha float32, x, y Vector, a General)

Ger performs a rank-1 update

A += alpha * x * yᵀ,

where A is an m×n dense matrix, x and y are vectors, and alpha is a scalar.

func Iamax

func Iamax(x Vector) int

Iamax returns the index of an element of x with the largest absolute value. If there are multiple such indices the earliest is returned. Iamax returns -1 if n == 0.

Iamax will panic if the vector increment is negative.

func Implementation

func Implementation() blas.Float32

Implementation returns the current BLAS float32 implementation.

Implementation allows direct calls to the current the BLAS float32 implementation giving finer control of parameters.

func Nrm2

func Nrm2(x Vector) float32

Nrm2 computes the Euclidean norm of the vector x:

sqrt(\sum_i x[i]*x[i]).

Nrm2 will panic if the vector increment is negative.

func Rot

func Rot(n int, x, y Vector, c, s float32)

Rot applies a plane transformation to n points represented by the vectors x and y:

x[i] =  c*x[i] + s*y[i],
y[i] = -s*x[i] + c*y[i], for all i.

func Rotg

func Rotg(a, b float32) (c, s, r, z float32)

Rotg computes the parameters of a Givens plane rotation so that

⎡ c s⎤   ⎡a⎤   ⎡r⎤
⎣-s c⎦ * ⎣b⎦ = ⎣0⎦

where a and b are the Cartesian coordinates of a given point. c, s, and r are defined as

r = ±Sqrt(a^2 + b^2),
c = a/r, the cosine of the rotation angle,
s = a/r, the sine of the rotation angle,

and z is defined such that

if |a| > |b|,        z = s,
otherwise if c != 0, z = 1/c,
otherwise            z = 1.

func Rotm

func Rotm(n int, x, y Vector, p blas.SrotmParams)

Rotm applies the modified Givens rotation to n points represented by the vectors x and y.

func Rotmg

func Rotmg(d1, d2, b1, b2 float32) (p blas.SrotmParams, rd1, rd2, rb1 float32)

Rotmg computes the modified Givens rotation. See http://www.netlib.org/lapack/explore-html/df/deb/drotmg_8f.html for more details.

func SDDot

func SDDot(alpha float32, x, y Vector) float32

SDDot computes the dot product of the two vectors adding a constant:

alpha + \sum_i x[i]*y[i].

SDDot will panic if the lengths of x and y do not match.

func Sbmv

func Sbmv(alpha float32, a SymmetricBand, x Vector, beta float32, y Vector)

Sbmv performs

y = alpha * A * x + beta * y,

where A is an n×n symmetric band matrix, x and y are vectors, and alpha and beta are scalars.

func Scal

func Scal(alpha float32, x Vector)

Scal scales the vector x by alpha:

x[i] *= alpha for all i.

Scal will panic if the vector increment is negative.

func Spmv

func Spmv(alpha float32, a SymmetricPacked, x Vector, beta float32, y Vector)

Spmv performs

y = alpha * A * x + beta * y,

where A is an n×n symmetric matrix in packed format, x and y are vectors, and alpha and beta are scalars.

func Spr

func Spr(alpha float32, x Vector, a SymmetricPacked)

Spr performs the rank-1 update

A += alpha * x * xᵀ,

where A is an n×n symmetric matrix in packed format, x is a vector, and alpha is a scalar.

func Spr2

func Spr2(alpha float32, x, y Vector, a SymmetricPacked)

Spr2 performs a rank-2 update

A += alpha * x * yᵀ + alpha * y * xᵀ,

where A is an n×n symmetric matrix in packed format, x and y are vectors, and alpha is a scalar.

func Swap

func Swap(x, y Vector)

Swap exchanges the elements of the two vectors:

x[i], y[i] = y[i], x[i] for all i.

Swap will panic if the lengths of x and y do not match.

func Symm

func Symm(s blas.Side, alpha float32, a Symmetric, b General, beta float32, c General)

Symm performs

C = alpha * A * B + beta * C  if s == blas.Left,
C = alpha * B * A + beta * C  if s == blas.Right,

where A is an n×n or m×m symmetric matrix, B and C are m×n matrices, and alpha is a scalar.

func Symv

func Symv(alpha float32, a Symmetric, x Vector, beta float32, y Vector)

Symv computes

y = alpha * A * x + beta * y,

where A is an n×n symmetric matrix, x and y are vectors, and alpha and beta are scalars.

func Syr

func Syr(alpha float32, x Vector, a Symmetric)

Syr performs a rank-1 update

A += alpha * x * xᵀ,

where A is an n×n symmetric matrix, x is a vector, and alpha is a scalar.

func Syr2

func Syr2(alpha float32, x, y Vector, a Symmetric)

Syr2 performs a rank-2 update

A += alpha * x * yᵀ + alpha * y * xᵀ,

where A is a symmetric n×n matrix, x and y are vectors, and alpha is a scalar.

func Syr2k

func Syr2k(t blas.Transpose, alpha float32, a, b General, beta float32, c Symmetric)

Syr2k performs a symmetric rank-2k update

C = alpha * A * Bᵀ + alpha * B * Aᵀ + beta * C  if t == blas.NoTrans,
C = alpha * Aᵀ * B + alpha * Bᵀ * A + beta * C  if t == blas.Trans or blas.ConjTrans,

where C is an n×n symmetric matrix, A and B are n×k matrices if t == NoTrans and k×n matrices otherwise, and alpha and beta are scalars.

func Syrk

func Syrk(t blas.Transpose, alpha float32, a General, beta float32, c Symmetric)

Syrk performs a symmetric rank-k update

C = alpha * A * Aᵀ + beta * C  if t == blas.NoTrans,
C = alpha * Aᵀ * A + beta * C  if t == blas.Trans or blas.ConjTrans,

where C is an n×n symmetric matrix, A is an n×k matrix if t == blas.NoTrans and a k×n matrix otherwise, and alpha and beta are scalars.

func Tbmv

func Tbmv(t blas.Transpose, a TriangularBand, x Vector)

Tbmv computes

x = A * x   if t == blas.NoTrans,
x = Aᵀ * x  if t == blas.Trans or blas.ConjTrans,

where A is an n×n triangular band matrix, and x is a vector.

func Tbsv

func Tbsv(t blas.Transpose, a TriangularBand, x Vector)

Tbsv solves

A * x = b   if t == blas.NoTrans,
Aᵀ * x = b  if t == blas.Trans or blas.ConjTrans,

where A is an n×n triangular band matrix, and x and b are vectors.

At entry to the function, x contains the values of b, and the result is stored in place into x.

No test for singularity or near-singularity is included in this routine. Such tests must be performed before calling this routine.

func Tpmv

func Tpmv(t blas.Transpose, a TriangularPacked, x Vector)

Tpmv computes

x = A * x   if t == blas.NoTrans,
x = Aᵀ * x  if t == blas.Trans or blas.ConjTrans,

where A is an n×n triangular matrix in packed format, and x is a vector.

func Tpsv

func Tpsv(t blas.Transpose, a TriangularPacked, x Vector)

Tpsv solves

A * x = b   if t == blas.NoTrans,
Aᵀ * x = b  if t == blas.Trans or blas.ConjTrans,

where A is an n×n triangular matrix in packed format, and x and b are vectors.

At entry to the function, x contains the values of b, and the result is stored in place into x.

No test for singularity or near-singularity is included in this routine. Such tests must be performed before calling this routine.

func Trmm

func Trmm(s blas.Side, tA blas.Transpose, alpha float32, a Triangular, b General)

Trmm performs

B = alpha * A * B   if tA == blas.NoTrans and s == blas.Left,
B = alpha * Aᵀ * B  if tA == blas.Trans or blas.ConjTrans, and s == blas.Left,
B = alpha * B * A   if tA == blas.NoTrans and s == blas.Right,
B = alpha * B * Aᵀ  if tA == blas.Trans or blas.ConjTrans, and s == blas.Right,

where A is an n×n or m×m triangular matrix, B is an m×n matrix, and alpha is a scalar.

func Trmv

func Trmv(t blas.Transpose, a Triangular, x Vector)

Trmv computes

x = A * x   if t == blas.NoTrans,
x = Aᵀ * x  if t == blas.Trans or blas.ConjTrans,

where A is an n×n triangular matrix, and x is a vector.

func Trsm

func Trsm(s blas.Side, tA blas.Transpose, alpha float32, a Triangular, b General)

Trsm solves

A * X = alpha * B   if tA == blas.NoTrans and s == blas.Left,
Aᵀ * X = alpha * B  if tA == blas.Trans or blas.ConjTrans, and s == blas.Left,
X * A = alpha * B   if tA == blas.NoTrans and s == blas.Right,
X * Aᵀ = alpha * B  if tA == blas.Trans or blas.ConjTrans, and s == blas.Right,

where A is an n×n or m×m triangular matrix, X and B are m×n matrices, and alpha is a scalar.

At entry to the function, X contains the values of B, and the result is stored in-place into X.

No check is made that A is invertible.

func Trsv

func Trsv(t blas.Transpose, a Triangular, x Vector)

Trsv solves

A * x = b   if t == blas.NoTrans,
Aᵀ * x = b  if t == blas.Trans or blas.ConjTrans,

where A is an n×n triangular matrix, and x and b are vectors.

At entry to the function, x contains the values of b, and the result is stored in-place into x.

No test for singularity or near-singularity is included in this routine. Such tests must be performed before calling this routine.

func Use

func Use(b blas.Float32)

Use sets the BLAS float32 implementation to be used by subsequent BLAS calls. The default implementation is gonum.org/v1/gonum/blas/gonum.Implementation.

type Band

type Band struct {
	Rows, Cols int
	KL, KU     int
	Stride     int
	Data       []float32
}

Band represents a band matrix using the band storage scheme.

func (Band) From

func (t Band) From(a BandCols)

From fills the receiver with elements from a. The receiver must have the same dimensions and bandwidth as a and have adequate backing data storage.

type BandCols

type BandCols Band

BandCols represents a matrix using the band column-major storage scheme.

func (BandCols) From

func (t BandCols) From(a Band)

From fills the receiver with elements from a. The receiver must have the same dimensions and bandwidth as a and have adequate backing data storage.

type General

type General struct {
	Rows, Cols int
	Stride     int
	Data       []float32
}

General represents a matrix using the conventional storage scheme.

func (General) From

func (t General) From(a GeneralCols)

From fills the receiver with elements from a. The receiver must have the same dimensions as a and have adequate backing data storage.

type GeneralCols

type GeneralCols General

GeneralCols represents a matrix using the conventional column-major storage scheme.

func (GeneralCols) From

func (t GeneralCols) From(a General)

From fills the receiver with elements from a. The receiver must have the same dimensions as a and have adequate backing data storage.

type Symmetric

type Symmetric struct {
	N      int
	Stride int
	Data   []float32
	Uplo   blas.Uplo
}

Symmetric represents a symmetric matrix using the conventional storage scheme.

func (Symmetric) From

func (t Symmetric) From(a SymmetricCols)

From fills the receiver with elements from a. The receiver must have the same dimensions and uplo as a and have adequate backing data storage.

type SymmetricBand

type SymmetricBand struct {
	N, K   int
	Stride int
	Data   []float32
	Uplo   blas.Uplo
}

SymmetricBand represents a symmetric matrix using the band storage scheme.

func (SymmetricBand) From

func (t SymmetricBand) From(a SymmetricBandCols)

From fills the receiver with elements from a. The receiver must have the same dimensions, bandwidth and uplo as a and have adequate backing data storage.

type SymmetricBandCols

type SymmetricBandCols SymmetricBand

SymmetricBandCols represents a symmetric matrix using the band column-major storage scheme.

func (SymmetricBandCols) From

func (t SymmetricBandCols) From(a SymmetricBand)

From fills the receiver with elements from a. The receiver must have the same dimensions, bandwidth and uplo as a and have adequate backing data storage.

type SymmetricCols

type SymmetricCols Symmetric

SymmetricCols represents a matrix using the conventional column-major storage scheme.

func (SymmetricCols) From

func (t SymmetricCols) From(a Symmetric)

From fills the receiver with elements from a. The receiver must have the same dimensions and uplo as a and have adequate backing data storage.

type SymmetricPacked

type SymmetricPacked struct {
	N    int
	Data []float32
	Uplo blas.Uplo
}

SymmetricPacked represents a symmetric matrix using the packed storage scheme.

type Triangular

type Triangular struct {
	N      int
	Stride int
	Data   []float32
	Uplo   blas.Uplo
	Diag   blas.Diag
}

Triangular represents a triangular matrix using the conventional storage scheme.

func (Triangular) From

func (t Triangular) From(a TriangularCols)

From fills the receiver with elements from a. The receiver must have the same dimensions, uplo and diag as a and have adequate backing data storage.

type TriangularBand

type TriangularBand struct {
	N, K   int
	Stride int
	Data   []float32
	Uplo   blas.Uplo
	Diag   blas.Diag
}

TriangularBand represents a triangular matrix using the band storage scheme.

func (TriangularBand) From

func (t TriangularBand) From(a TriangularBandCols)

From fills the receiver with elements from a. The receiver must have the same dimensions, bandwidth and uplo as a and have adequate backing data storage.

type TriangularBandCols

type TriangularBandCols TriangularBand

TriangularBandCols represents a triangular matrix using the band column-major storage scheme.

func (TriangularBandCols) From

func (t TriangularBandCols) From(a TriangularBand)

From fills the receiver with elements from a. The receiver must have the same dimensions, bandwidth and uplo as a and have adequate backing data storage.

type TriangularCols

type TriangularCols Triangular

TriangularCols represents a matrix using the conventional column-major storage scheme.

func (TriangularCols) From

func (t TriangularCols) From(a Triangular)

From fills the receiver with elements from a. The receiver must have the same dimensions, uplo and diag as a and have adequate backing data storage.

type TriangularPacked

type TriangularPacked struct {
	N    int
	Data []float32
	Uplo blas.Uplo
	Diag blas.Diag
}

TriangularPacked represents a triangular matrix using the packed storage scheme.

type Vector

type Vector struct {
	N    int
	Inc  int
	Data []float32
}

Vector represents a vector with an associated element increment.

Package Files

Documentation was rendered with GOOS=linux and GOARCH=amd64.

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