feat(modules): migrate to go modules and bump go version 1.14.4

- migrate to go module
- bump go version 1.14.4

Signed-off-by: prateekpandey14 <prateek.pandey@mayadata.io>

vendor/gonum.org/v1/gonum/mat/vector.go

@@ -0,0 +1,741 @@
+// Copyright ©2013 The Gonum Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mat
+
+import (
+	"gonum.org/v1/gonum/blas"
+	"gonum.org/v1/gonum/blas/blas64"
+	"gonum.org/v1/gonum/internal/asm/f64"
+)
+
+var (
+	vector *VecDense
+
+	_ Matrix  = vector
+	_ Vector  = vector
+	_ Reseter = vector
+)
+
+// Vector is a vector.
+type Vector interface {
+	Matrix
+	AtVec(int) float64
+	Len() int
+}
+
+// TransposeVec is a type for performing an implicit transpose of a Vector.
+// It implements the Vector interface, returning values from the transpose
+// of the vector within.
+type TransposeVec struct {
+	Vector Vector
+}
+
+// At returns the value of the element at row i and column j of the transposed
+// matrix, that is, row j and column i of the Vector field.
+func (t TransposeVec) At(i, j int) float64 {
+	return t.Vector.At(j, i)
+}
+
+// AtVec returns the element at position i. It panics if i is out of bounds.
+func (t TransposeVec) AtVec(i int) float64 {
+	return t.Vector.AtVec(i)
+}
+
+// Dims returns the dimensions of the transposed vector.
+func (t TransposeVec) Dims() (r, c int) {
+	c, r = t.Vector.Dims()
+	return r, c
+}
+
+// T performs an implicit transpose by returning the Vector field.
+func (t TransposeVec) T() Matrix {
+	return t.Vector
+}
+
+// Len returns the number of columns in the vector.
+func (t TransposeVec) Len() int {
+	return t.Vector.Len()
+}
+
+// TVec performs an implicit transpose by returning the Vector field.
+func (t TransposeVec) TVec() Vector {
+	return t.Vector
+}
+
+// Untranspose returns the Vector field.
+func (t TransposeVec) Untranspose() Matrix {
+	return t.Vector
+}
+
+func (t TransposeVec) UntransposeVec() Vector {
+	return t.Vector
+}
+
+// VecDense represents a column vector.
+type VecDense struct {
+	mat blas64.Vector
+	// A BLAS vector can have a negative increment, but allowing this
+	// in the mat type complicates a lot of code, and doesn't gain anything.
+	// VecDense must have positive increment in this package.
+}
+
+// NewVecDense creates a new VecDense of length n. If data == nil,
+// a new slice is allocated for the backing slice. If len(data) == n, data is
+// used as the backing slice, and changes to the elements of the returned VecDense
+// will be reflected in data. If neither of these is true, NewVecDense will panic.
+// NewVecDense will panic if n is zero.
+func NewVecDense(n int, data []float64) *VecDense {
+	if n <= 0 {
+		if n == 0 {
+			panic(ErrZeroLength)
+		}
+		panic("mat: negative dimension")
+	}
+	if len(data) != n && data != nil {
+		panic(ErrShape)
+	}
+	if data == nil {
+		data = make([]float64, n)
+	}
+	return &VecDense{
+		mat: blas64.Vector{
+			N:    n,
+			Inc:  1,
+			Data: data,
+		},
+	}
+}
+
+// SliceVec returns a new Vector that shares backing data with the receiver.
+// The returned matrix starts at i of the receiver and extends k-i elements.
+// SliceVec panics with ErrIndexOutOfRange if the slice is outside the capacity
+// of the receiver.
+func (v *VecDense) SliceVec(i, k int) Vector {
+	if i < 0 || k <= i || v.Cap() < k {
+		panic(ErrIndexOutOfRange)
+	}
+	return &VecDense{
+		mat: blas64.Vector{
+			N:    k - i,
+			Inc:  v.mat.Inc,
+			Data: v.mat.Data[i*v.mat.Inc : (k-1)*v.mat.Inc+1],
+		},
+	}
+}
+
+// Dims returns the number of rows and columns in the matrix. Columns is always 1
+// for a non-Reset vector.
+func (v *VecDense) Dims() (r, c int) {
+	if v.IsZero() {
+		return 0, 0
+	}
+	return v.mat.N, 1
+}
+
+// Caps returns the number of rows and columns in the backing matrix. Columns is always 1
+// for a non-Reset vector.
+func (v *VecDense) Caps() (r, c int) {
+	if v.IsZero() {
+		return 0, 0
+	}
+	return v.Cap(), 1
+}
+
+// Len returns the length of the vector.
+func (v *VecDense) Len() int {
+	return v.mat.N
+}
+
+// Cap returns the capacity of the vector.
+func (v *VecDense) Cap() int {
+	if v.IsZero() {
+		return 0
+	}
+	return (cap(v.mat.Data)-1)/v.mat.Inc + 1
+}
+
+// T performs an implicit transpose by returning the receiver inside a Transpose.
+func (v *VecDense) T() Matrix {
+	return Transpose{v}
+}
+
+// TVec performs an implicit transpose by returning the receiver inside a TransposeVec.
+func (v *VecDense) TVec() Vector {
+	return TransposeVec{v}
+}
+
+// Reset zeros the length of the vector so that it can be reused as the
+// receiver of a dimensionally restricted operation.
+//
+// See the Reseter interface for more information.
+func (v *VecDense) Reset() {
+	// No change of Inc or N to 0 may be
+	// made unless both are set to 0.
+	v.mat.Inc = 0
+	v.mat.N = 0
+	v.mat.Data = v.mat.Data[:0]
+}
+
+// Zero sets all of the matrix elements to zero.
+func (v *VecDense) Zero() {
+	for i := 0; i < v.mat.N; i++ {
+		v.mat.Data[v.mat.Inc*i] = 0
+	}
+}
+
+// CloneVec makes a copy of a into the receiver, overwriting the previous value
+// of the receiver.
+func (v *VecDense) CloneVec(a Vector) {
+	if v == a {
+		return
+	}
+	n := a.Len()
+	v.mat = blas64.Vector{
+		N:    n,
+		Inc:  1,
+		Data: use(v.mat.Data, n),
+	}
+	if r, ok := a.(RawVectorer); ok {
+		blas64.Copy(r.RawVector(), v.mat)
+		return
+	}
+	for i := 0; i < a.Len(); i++ {
+		v.SetVec(i, a.AtVec(i))
+	}
+}
+
+// VecDenseCopyOf returns a newly allocated copy of the elements of a.
+func VecDenseCopyOf(a Vector) *VecDense {
+	v := &VecDense{}
+	v.CloneVec(a)
+	return v
+}
+
+func (v *VecDense) RawVector() blas64.Vector {
+	return v.mat
+}
+
+// CopyVec makes a copy of elements of a into the receiver. It is similar to the
+// built-in copy; it copies as much as the overlap between the two vectors and
+// returns the number of elements it copied.
+func (v *VecDense) CopyVec(a Vector) int {
+	n := min(v.Len(), a.Len())
+	if v == a {
+		return n
+	}
+	if r, ok := a.(RawVectorer); ok {
+		blas64.Copy(r.RawVector(), v.mat)
+		return n
+	}
+	for i := 0; i < n; i++ {
+		v.setVec(i, a.AtVec(i))
+	}
+	return n
+}
+
+// ScaleVec scales the vector a by alpha, placing the result in the receiver.
+func (v *VecDense) ScaleVec(alpha float64, a Vector) {
+	n := a.Len()
+
+	if v == a {
+		if v.mat.Inc == 1 {
+			f64.ScalUnitary(alpha, v.mat.Data)
+			return
+		}
+		f64.ScalInc(alpha, v.mat.Data, uintptr(n), uintptr(v.mat.Inc))
+		return
+	}
+
+	v.reuseAs(n)
+
+	if rv, ok := a.(RawVectorer); ok {
+		mat := rv.RawVector()
+		v.checkOverlap(mat)
+		if v.mat.Inc == 1 && mat.Inc == 1 {
+			f64.ScalUnitaryTo(v.mat.Data, alpha, mat.Data)
+			return
+		}
+		f64.ScalIncTo(v.mat.Data, uintptr(v.mat.Inc),
+			alpha, mat.Data, uintptr(n), uintptr(mat.Inc))
+		return
+	}
+
+	for i := 0; i < n; i++ {
+		v.setVec(i, alpha*a.AtVec(i))
+	}
+}
+
+// AddScaledVec adds the vectors a and alpha*b, placing the result in the receiver.
+func (v *VecDense) AddScaledVec(a Vector, alpha float64, b Vector) {
+	if alpha == 1 {
+		v.AddVec(a, b)
+		return
+	}
+	if alpha == -1 {
+		v.SubVec(a, b)
+		return
+	}
+
+	ar := a.Len()
+	br := b.Len()
+
+	if ar != br {
+		panic(ErrShape)
+	}
+
+	var amat, bmat blas64.Vector
+	fast := true
+	aU, _ := untranspose(a)
+	if rv, ok := aU.(RawVectorer); ok {
+		amat = rv.RawVector()
+		if v != a {
+			v.checkOverlap(amat)
+		}
+	} else {
+		fast = false
+	}
+	bU, _ := untranspose(b)
+	if rv, ok := bU.(RawVectorer); ok {
+		bmat = rv.RawVector()
+		if v != b {
+			v.checkOverlap(bmat)
+		}
+	} else {
+		fast = false
+	}
+
+	v.reuseAs(ar)
+
+	switch {
+	case alpha == 0: // v <- a
+		if v == a {
+			return
+		}
+		v.CopyVec(a)
+	case v == a && v == b: // v <- v + alpha * v = (alpha + 1) * v
+		blas64.Scal(alpha+1, v.mat)
+	case !fast: // v <- a + alpha * b without blas64 support.
+		for i := 0; i < ar; i++ {
+			v.setVec(i, a.AtVec(i)+alpha*b.AtVec(i))
+		}
+	case v == a && v != b: // v <- v + alpha * b
+		if v.mat.Inc == 1 && bmat.Inc == 1 {
+			// Fast path for a common case.
+			f64.AxpyUnitaryTo(v.mat.Data, alpha, bmat.Data, amat.Data)
+		} else {
+			f64.AxpyInc(alpha, bmat.Data, v.mat.Data,
+				uintptr(ar), uintptr(bmat.Inc), uintptr(v.mat.Inc), 0, 0)
+		}
+	default: // v <- a + alpha * b or v <- a + alpha * v
+		if v.mat.Inc == 1 && amat.Inc == 1 && bmat.Inc == 1 {
+			// Fast path for a common case.
+			f64.AxpyUnitaryTo(v.mat.Data, alpha, bmat.Data, amat.Data)
+		} else {
+			f64.AxpyIncTo(v.mat.Data, uintptr(v.mat.Inc), 0,
+				alpha, bmat.Data, amat.Data,
+				uintptr(ar), uintptr(bmat.Inc), uintptr(amat.Inc), 0, 0)
+		}
+	}
+}
+
+// AddVec adds the vectors a and b, placing the result in the receiver.
+func (v *VecDense) AddVec(a, b Vector) {
+	ar := a.Len()
+	br := b.Len()
+
+	if ar != br {
+		panic(ErrShape)
+	}
+
+	v.reuseAs(ar)
+
+	aU, _ := untranspose(a)
+	bU, _ := untranspose(b)
+
+	if arv, ok := aU.(RawVectorer); ok {
+		if brv, ok := bU.(RawVectorer); ok {
+			amat := arv.RawVector()
+			bmat := brv.RawVector()
+
+			if v != a {
+				v.checkOverlap(amat)
+			}
+			if v != b {
+				v.checkOverlap(bmat)
+			}
+
+			if v.mat.Inc == 1 && amat.Inc == 1 && bmat.Inc == 1 {
+				// Fast path for a common case.
+				f64.AxpyUnitaryTo(v.mat.Data, 1, bmat.Data, amat.Data)
+				return
+			}
+			f64.AxpyIncTo(v.mat.Data, uintptr(v.mat.Inc), 0,
+				1, bmat.Data, amat.Data,
+				uintptr(ar), uintptr(bmat.Inc), uintptr(amat.Inc), 0, 0)
+			return
+		}
+	}
+
+	for i := 0; i < ar; i++ {
+		v.setVec(i, a.AtVec(i)+b.AtVec(i))
+	}
+}
+
+// SubVec subtracts the vector b from a, placing the result in the receiver.
+func (v *VecDense) SubVec(a, b Vector) {
+	ar := a.Len()
+	br := b.Len()
+
+	if ar != br {
+		panic(ErrShape)
+	}
+
+	v.reuseAs(ar)
+
+	aU, _ := untranspose(a)
+	bU, _ := untranspose(b)
+
+	if arv, ok := aU.(RawVectorer); ok {
+		if brv, ok := bU.(RawVectorer); ok {
+			amat := arv.RawVector()
+			bmat := brv.RawVector()
+
+			if v != a {
+				v.checkOverlap(amat)
+			}
+			if v != b {
+				v.checkOverlap(bmat)
+			}
+
+			if v.mat.Inc == 1 && amat.Inc == 1 && bmat.Inc == 1 {
+				// Fast path for a common case.
+				f64.AxpyUnitaryTo(v.mat.Data, -1, bmat.Data, amat.Data)
+				return
+			}
+			f64.AxpyIncTo(v.mat.Data, uintptr(v.mat.Inc), 0,
+				-1, bmat.Data, amat.Data,
+				uintptr(ar), uintptr(bmat.Inc), uintptr(amat.Inc), 0, 0)
+			return
+		}
+	}
+
+	for i := 0; i < ar; i++ {
+		v.setVec(i, a.AtVec(i)-b.AtVec(i))
+	}
+}
+
+// MulElemVec performs element-wise multiplication of a and b, placing the result
+// in the receiver.
+func (v *VecDense) MulElemVec(a, b Vector) {
+	ar := a.Len()
+	br := b.Len()
+
+	if ar != br {
+		panic(ErrShape)
+	}
+
+	v.reuseAs(ar)
+
+	aU, _ := untranspose(a)
+	bU, _ := untranspose(b)
+
+	if arv, ok := aU.(RawVectorer); ok {
+		if brv, ok := bU.(RawVectorer); ok {
+			amat := arv.RawVector()
+			bmat := brv.RawVector()
+
+			if v != a {
+				v.checkOverlap(amat)
+			}
+			if v != b {
+				v.checkOverlap(bmat)
+			}
+
+			if v.mat.Inc == 1 && amat.Inc == 1 && bmat.Inc == 1 {
+				// Fast path for a common case.
+				for i, a := range amat.Data {
+					v.mat.Data[i] = a * bmat.Data[i]
+				}
+				return
+			}
+			var ia, ib int
+			for i := 0; i < ar; i++ {
+				v.setVec(i, amat.Data[ia]*bmat.Data[ib])
+				ia += amat.Inc
+				ib += bmat.Inc
+			}
+			return
+		}
+	}
+
+	for i := 0; i < ar; i++ {
+		v.setVec(i, a.AtVec(i)*b.AtVec(i))
+	}
+}
+
+// DivElemVec performs element-wise division of a by b, placing the result
+// in the receiver.
+func (v *VecDense) DivElemVec(a, b Vector) {
+	ar := a.Len()
+	br := b.Len()
+
+	if ar != br {
+		panic(ErrShape)
+	}
+
+	v.reuseAs(ar)
+
+	aU, _ := untranspose(a)
+	bU, _ := untranspose(b)
+
+	if arv, ok := aU.(RawVectorer); ok {
+		if brv, ok := bU.(RawVectorer); ok {
+			amat := arv.RawVector()
+			bmat := brv.RawVector()
+
+			if v != a {
+				v.checkOverlap(amat)
+			}
+			if v != b {
+				v.checkOverlap(bmat)
+			}
+
+			if v.mat.Inc == 1 && amat.Inc == 1 && bmat.Inc == 1 {
+				// Fast path for a common case.
+				for i, a := range amat.Data {
+					v.setVec(i, a/bmat.Data[i])
+				}
+				return
+			}
+			var ia, ib int
+			for i := 0; i < ar; i++ {
+				v.setVec(i, amat.Data[ia]/bmat.Data[ib])
+				ia += amat.Inc
+				ib += bmat.Inc
+			}
+		}
+	}
+
+	for i := 0; i < ar; i++ {
+		v.setVec(i, a.AtVec(i)/b.AtVec(i))
+	}
+}
+
+// MulVec computes a * b. The result is stored into the receiver.
+// MulVec panics if the number of columns in a does not equal the number of rows in b
+// or if the number of columns in b does not equal 1.
+func (v *VecDense) MulVec(a Matrix, b Vector) {
+	r, c := a.Dims()
+	br, bc := b.Dims()
+	if c != br || bc != 1 {
+		panic(ErrShape)
+	}
+
+	aU, trans := untranspose(a)
+	var bmat blas64.Vector
+	fast := true
+	bU, _ := untranspose(b)
+	if rv, ok := bU.(RawVectorer); ok {
+		bmat = rv.RawVector()
+		if v != b {
+			v.checkOverlap(bmat)
+		}
+	} else {
+		fast = false
+	}
+
+	v.reuseAs(r)
+	var restore func()
+	if v == aU {
+		v, restore = v.isolatedWorkspace(aU.(*VecDense))
+		defer restore()
+	} else if v == b {
+		v, restore = v.isolatedWorkspace(b)
+		defer restore()
+	}
+
+	// TODO(kortschak): Improve the non-fast paths.
+	switch aU := aU.(type) {
+	case Vector:
+		if b.Len() == 1 {
+			// {n,1} x {1,1}
+			v.ScaleVec(b.AtVec(0), aU)
+			return
+		}
+
+		// {1,n} x {n,1}
+		if fast {
+			if rv, ok := aU.(RawVectorer); ok {
+				amat := rv.RawVector()
+				if v != aU {
+					v.checkOverlap(amat)
+				}
+
+				if amat.Inc == 1 && bmat.Inc == 1 {
+					// Fast path for a common case.
+					v.setVec(0, f64.DotUnitary(amat.Data, bmat.Data))
+					return
+				}
+				v.setVec(0, f64.DotInc(amat.Data, bmat.Data,
+					uintptr(c), uintptr(amat.Inc), uintptr(bmat.Inc), 0, 0))
+				return
+			}
+		}
+		var sum float64
+		for i := 0; i < c; i++ {
+			sum += aU.AtVec(i) * b.AtVec(i)
+		}
+		v.setVec(0, sum)
+		return
+	case RawSymmetricer:
+		if fast {
+			amat := aU.RawSymmetric()
+			// We don't know that a is a *SymDense, so make
+			// a temporary SymDense to check overlap.
+			(&SymDense{mat: amat}).checkOverlap(v.asGeneral())
+			blas64.Symv(1, amat, bmat, 0, v.mat)
+			return
+		}
+	case RawTriangular:
+		v.CopyVec(b)
+		amat := aU.RawTriangular()
+		// We don't know that a is a *TriDense, so make
+		// a temporary TriDense to check overlap.
+		(&TriDense{mat: amat}).checkOverlap(v.asGeneral())
+		ta := blas.NoTrans
+		if trans {
+			ta = blas.Trans
+		}
+		blas64.Trmv(ta, amat, v.mat)
+	case RawMatrixer:
+		if fast {
+			amat := aU.RawMatrix()
+			// We don't know that a is a *Dense, so make
+			// a temporary Dense to check overlap.
+			(&Dense{mat: amat}).checkOverlap(v.asGeneral())
+			t := blas.NoTrans
+			if trans {
+				t = blas.Trans
+			}
+			blas64.Gemv(t, 1, amat, bmat, 0, v.mat)
+			return
+		}
+	default:
+		if fast {
+			for i := 0; i < r; i++ {
+				var f float64
+				for j := 0; j < c; j++ {
+					f += a.At(i, j) * bmat.Data[j*bmat.Inc]
+				}
+				v.setVec(i, f)
+			}
+			return
+		}
+	}
+
+	for i := 0; i < r; i++ {
+		var f float64
+		for j := 0; j < c; j++ {
+			f += a.At(i, j) * b.AtVec(j)
+		}
+		v.setVec(i, f)
+	}
+}
+
+// reuseAs resizes an empty vector to a r×1 vector,
+// or checks that a non-empty matrix is r×1.
+func (v *VecDense) reuseAs(r int) {
+	if r == 0 {
+		panic(ErrZeroLength)
+	}
+	if v.IsZero() {
+		v.mat = blas64.Vector{
+			N:    r,
+			Inc:  1,
+			Data: use(v.mat.Data, r),
+		}
+		return
+	}
+	if r != v.mat.N {
+		panic(ErrShape)
+	}
+}
+
+// IsZero returns whether the receiver is zero-sized. Zero-sized vectors can be the
+// receiver for size-restricted operations. VecDenses can be zeroed using Reset.
+func (v *VecDense) IsZero() bool {
+	// It must be the case that v.Dims() returns
+	// zeros in this case. See comment in Reset().
+	return v.mat.Inc == 0
+}
+
+func (v *VecDense) isolatedWorkspace(a Vector) (n *VecDense, restore func()) {
+	l := a.Len()
+	if l == 0 {
+		panic(ErrZeroLength)
+	}
+	n = getWorkspaceVec(l, false)
+	return n, func() {
+		v.CopyVec(n)
+		putWorkspaceVec(n)
+	}
+}
+
+// asDense returns a Dense representation of the receiver with the same
+// underlying data.
+func (v *VecDense) asDense() *Dense {
+	return &Dense{
+		mat:     v.asGeneral(),
+		capRows: v.mat.N,
+		capCols: 1,
+	}
+}
+
+// asGeneral returns a blas64.General representation of the receiver with the
+// same underlying data.
+func (v *VecDense) asGeneral() blas64.General {
+	return blas64.General{
+		Rows:   v.mat.N,
+		Cols:   1,
+		Stride: v.mat.Inc,
+		Data:   v.mat.Data,
+	}
+}
+
+// ColViewOf reflects the column j of the RawMatrixer m, into the receiver
+// backed by the same underlying data. The length of the receiver must either be
+// zero or match the number of rows in m.
+func (v *VecDense) ColViewOf(m RawMatrixer, j int) {
+	rm := m.RawMatrix()
+
+	if j >= rm.Cols || j < 0 {
+		panic(ErrColAccess)
+	}
+	if !v.IsZero() && v.mat.N != rm.Rows {
+		panic(ErrShape)
+	}
+
+	v.mat.Inc = rm.Stride
+	v.mat.Data = rm.Data[j : (rm.Rows-1)*rm.Stride+j+1]
+	v.mat.N = rm.Rows
+}
+
+// RowViewOf reflects the row i of the RawMatrixer m, into the receiver
+// backed by the same underlying data. The length of the receiver must either be
+// zero or match the number of columns in m.
+func (v *VecDense) RowViewOf(m RawMatrixer, i int) {
+	rm := m.RawMatrix()
+
+	if i >= rm.Rows || i < 0 {
+		panic(ErrRowAccess)
+	}
+	if !v.IsZero() && v.mat.N != rm.Cols {
+		panic(ErrShape)
+	}
+
+	v.mat.Inc = 1
+	v.mat.Data = rm.Data[i*rm.Stride : i*rm.Stride+rm.Cols]
+	v.mat.N = rm.Cols
+}