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Package f64

v0.7.0
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Published: Feb 26, 2020 | License: BSD-3-Clause | Module: gonum.org/v1/gonum

Overview

Package f64 provides float64 vector primitives.

Index

Package Files

func Add

func Add(dst, s []float64)

Add is

for i, v := range s {
	dst[i] += v
}

func AddConst

func AddConst(alpha float64, x []float64)

AddConst is

for i := range x {
	x[i] += alpha
}

func AxpyInc

func AxpyInc(alpha float64, x, y []float64, n, incX, incY, ix, iy uintptr)

AxpyInc is

for i := 0; i < int(n); i++ {
	y[iy] += alpha * x[ix]
	ix += incX
	iy += incY
}

func AxpyIncTo

func AxpyIncTo(dst []float64, incDst, idst uintptr, alpha float64, x, y []float64, n, incX, incY, ix, iy uintptr)

AxpyIncTo is

for i := 0; i < int(n); i++ {
	dst[idst] = alpha*x[ix] + y[iy]
	ix += incX
	iy += incY
	idst += incDst
}

func AxpyUnitary

func AxpyUnitary(alpha float64, x, y []float64)

AxpyUnitary is

for i, v := range x {
	y[i] += alpha * v
}

func AxpyUnitaryTo

func AxpyUnitaryTo(dst []float64, alpha float64, x, y []float64)

AxpyUnitaryTo is

for i, v := range x {
	dst[i] = alpha*v + y[i]
}

func CumProd

func CumProd(dst, s []float64) []float64

CumProd is

if len(s) == 0 {
	return dst
}
dst[0] = s[0]
for i, v := range s[1:] {
	dst[i+1] = dst[i] * v
}
return dst

func CumSum

func CumSum(dst, s []float64) []float64

CumSum is

if len(s) == 0 {
	return dst
}
dst[0] = s[0]
for i, v := range s[1:] {
	dst[i+1] = dst[i] + v
}
return dst

func Div

func Div(dst, s []float64)

Div is

for i, v := range s {
	dst[i] /= v
}

func DivTo

func DivTo(dst, x, y []float64) []float64

DivTo is

for i, v := range s {
	dst[i] = v / t[i]
}
return dst

func DotInc

func DotInc(x, y []float64, n, incX, incY, ix, iy uintptr) (sum float64)

DotInc is

for i := 0; i < int(n); i++ {
	sum += y[iy] * x[ix]
	ix += incX
	iy += incY
}
return sum

func DotUnitary

func DotUnitary(x, y []float64) (sum float64)

DotUnitary is

for i, v := range x {
	sum += y[i] * v
}
return sum

func GemvN

func GemvN(m, n uintptr, alpha float64, a []float64, lda uintptr, x []float64, incX uintptr, beta float64, y []float64, incY uintptr)

GemvN computes

y = alpha * A * x + beta * y

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

func GemvT

func GemvT(m, n uintptr, alpha float64, a []float64, lda uintptr, x []float64, incX uintptr, beta float64, y []float64, incY uintptr)

GemvT computes

y = alpha * Aᵀ * x + beta * y

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

func Ger

func Ger(m, n uintptr, alpha float64, x []float64, incX uintptr, y []float64, incY uintptr, a []float64, lda uintptr)

Ger performs the rank-one operation

A += alpha * x * yᵀ

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

func L1Dist

func L1Dist(s, t []float64) float64

L1Dist is

var norm float64
for i, v := range s {
	norm += math.Abs(t[i] - v)
}
return norm

func L1Norm

func L1Norm(x []float64) (sum float64)

L1Norm is

for _, v := range x {
	sum += math.Abs(v)
}
return sum

func L1NormInc

func L1NormInc(x []float64, n, incX int) (sum float64)

L1NormInc is

for i := 0; i < n*incX; i += incX {
	sum += math.Abs(x[i])
}
return sum

func L2DistanceUnitary

func L2DistanceUnitary(x, y []float64) (norm float64)

L2DistanceUnitary returns the L2-norm of x-y.

var scale float64
sumSquares := 1.0
for i, v := range x {
	v -= y[i]
	if v == 0 {
		continue
	}
	absxi := math.Abs(v)
	if math.IsNaN(absxi) {
		return math.NaN()
	}
	if scale < absxi {
		s := scale / absxi
		sumSquares = 1 + sumSquares*s*s
		scale = absxi
	} else {
		s := absxi / scale
		sumSquares += s * s
	}
}
if math.IsInf(scale, 1) {
	return math.Inf(1)
}
return scale * math.Sqrt(sumSquares)

func L2NormInc

func L2NormInc(x []float64, n, incX uintptr) (norm float64)

L2NormInc returns the L2-norm of x.

var scale float64
sumSquares := 1.0
for ix := uintptr(0); ix < n*incX; ix += incX {
	val := x[ix]
	if val == 0 {
		continue
	}
	absxi := math.Abs(val)
	if math.IsNaN(absxi) {
		return math.NaN()
	}
	if scale < absxi {
		s := scale / absxi
		sumSquares = 1 + sumSquares*s*s
		scale = absxi
	} else {
		s := absxi / scale
		sumSquares += s * s
	}
}
if math.IsInf(scale, 1) {
	return math.Inf(1)
}
return scale * math.Sqrt(sumSquares)

func L2NormUnitary

func L2NormUnitary(x []float64) (norm float64)

L2NormUnitary returns the L2-norm of x.

  var scale float64
  sumSquares := 1.0
  for _, v := range x {
  	if v == 0 {
  		continue
  	}
  	absxi := math.Abs(v)
  	if math.IsNaN(absxi) {
  		return math.NaN()
  	}
  	if scale < absxi {
  		s := scale / absxi
  		sumSquares = 1 + sumSquares*s*s
  		scale = absxi
  	} else {
  		s := absxi / scale
  		sumSquares += s * s
  	}
	  	if math.IsInf(scale, 1) {
		  	return math.Inf(1)
	  	}
  }
  return scale * math.Sqrt(sumSquares)

func LinfDist

func LinfDist(s, t []float64) float64

LinfDist is

var norm float64
if len(s) == 0 {
	return 0
}
norm = math.Abs(t[0] - s[0])
for i, v := range s[1:] {
	absDiff := math.Abs(t[i+1] - v)
	if absDiff > norm || math.IsNaN(norm) {
		norm = absDiff
	}
}
return norm

func ScalInc

func ScalInc(alpha float64, x []float64, n, incX uintptr)

ScalInc is

var ix uintptr
for i := 0; i < int(n); i++ {
	x[ix] *= alpha
	ix += incX
}

func ScalIncTo

func ScalIncTo(dst []float64, incDst uintptr, alpha float64, x []float64, n, incX uintptr)

ScalIncTo is

var idst, ix uintptr
for i := 0; i < int(n); i++ {
	dst[idst] = alpha * x[ix]
	ix += incX
	idst += incDst
}

func ScalUnitary

func ScalUnitary(alpha float64, x []float64)

ScalUnitary is

for i := range x {
	x[i] *= alpha
}

func ScalUnitaryTo

func ScalUnitaryTo(dst []float64, alpha float64, x []float64)

ScalUnitaryTo is

for i, v := range x {
	dst[i] = alpha * v
}

func Sum

func Sum(x []float64) float64

Sum is

var sum float64
for i := range x {
    sum += x[i]
}
Documentation was rendered with GOOS=linux and GOARCH=amd64.

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