mirror of
https://github.com/gonum/gonum.git
synced 2025-10-22 06:39:26 +08:00
ec100cf00f
Improved function documentation Fixed dlarfb and dlarft and added full tests Added dgelq2 Working Dgels Fix many comments and tests Many PR comment responses Responded to more PR comments Many PR comments
93 lines
2.4 KiB
Go
93 lines
2.4 KiB
Go
// Copyright ©2015 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 native
|
|
|
|
import (
|
|
"math"
|
|
|
|
"github.com/gonum/lapack"
|
|
)
|
|
|
|
// Implementation is the native Go implementation of LAPACK routines. It
|
|
// is built on top of calls to the return of blas64.Implementation(), so while
|
|
// this code is in pure Go, the underlying BLAS implementation may not be.
|
|
type Implementation struct{}
|
|
|
|
var _ lapack.Float64 = Implementation{}
|
|
|
|
const (
|
|
badDirect = "lapack: bad direct"
|
|
badLdA = "lapack: index of a out of range"
|
|
badSide = "lapack: bad side"
|
|
badStore = "lapack: bad store"
|
|
badTau = "lapack: tau has insufficient length"
|
|
badTrans = "lapack: bad trans"
|
|
badUplo = "lapack: illegal triangle"
|
|
badWork = "lapack: insufficient working memory"
|
|
badWorkStride = "lapack: insufficient working array stride"
|
|
negDimension = "lapack: negative matrix dimension"
|
|
nLT0 = "lapack: n < 0"
|
|
shortWork = "lapack: working array shorter than declared"
|
|
)
|
|
|
|
// checkMatrix verifies the parameters of a matrix input.
|
|
func checkMatrix(m, n int, a []float64, lda int) {
|
|
if m < 0 {
|
|
panic("lapack: has negative number of rows")
|
|
}
|
|
if m < 0 {
|
|
panic("lapack: has negative number of columns")
|
|
}
|
|
if lda < n {
|
|
panic("lapack: stride less than number of columns")
|
|
}
|
|
if len(a) < (m-1)*lda+n {
|
|
panic("lapack: insufficient matrix slice length")
|
|
}
|
|
}
|
|
|
|
func checkVector(n int, v []float64, inc int) {
|
|
if n < 0 {
|
|
panic("lapack: negative matrix length")
|
|
}
|
|
if (inc > 0 && (n-1)*inc >= len(v)) || (inc < 0 && (1-n)*inc >= len(v)) {
|
|
panic("lapack: insufficient vector slice length")
|
|
}
|
|
}
|
|
|
|
func min(a, b int) int {
|
|
if a < b {
|
|
return a
|
|
}
|
|
return b
|
|
}
|
|
|
|
func max(a, b int) int {
|
|
if a > b {
|
|
return a
|
|
}
|
|
return b
|
|
}
|
|
|
|
// dlamch is a function in fortran, but since go forces IEEE-754 these are all
|
|
// fixed values. Probably a way to get them as constants.
|
|
// TODO(btracey): Is there a better way to find the smallest number such that 1+E > 1
|
|
|
|
var dlamchE, dlamchS, dlamchP float64
|
|
|
|
func init() {
|
|
onePlusEps := math.Nextafter(1, math.Inf(1))
|
|
eps := (math.Nextafter(1, math.Inf(1)) - 1) * 0.5
|
|
dlamchE = eps
|
|
sfmin := math.SmallestNonzeroFloat64
|
|
small := 1 / math.MaxFloat64
|
|
if small >= sfmin {
|
|
sfmin = small * onePlusEps
|
|
}
|
|
dlamchS = sfmin
|
|
radix := 2.0
|
|
dlamchP = radix * eps
|
|
}
|