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https://github.com/TECHNOFAB11/zfs-localpv.git
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fa76b346a0
- migrate to go module - bump go version 1.14.4 Signed-off-by: prateekpandey14 <prateek.pandey@mayadata.io>
64 lines
1.5 KiB
Go
64 lines
1.5 KiB
Go
// Copyright ©2018 The Gonum Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package gonum
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import (
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"gonum.org/v1/gonum/blas"
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"gonum.org/v1/gonum/blas/blas64"
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)
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// Dlauu2 computes the product
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// U * U^T if uplo is blas.Upper
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// L^T * L if uplo is blas.Lower
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// where U or L is stored in the upper or lower triangular part of A.
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// Only the upper or lower triangle of the result is stored, overwriting
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// the corresponding factor in A.
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func (impl Implementation) Dlauu2(uplo blas.Uplo, n int, a []float64, lda int) {
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switch {
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case uplo != blas.Upper && uplo != blas.Lower:
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panic(badUplo)
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case n < 0:
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panic(nLT0)
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case lda < max(1, n):
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panic(badLdA)
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}
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// Quick return if possible.
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if n == 0 {
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return
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}
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if len(a) < (n-1)*lda+n {
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panic(shortA)
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}
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bi := blas64.Implementation()
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if uplo == blas.Upper {
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// Compute the product U*U^T.
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for i := 0; i < n; i++ {
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aii := a[i*lda+i]
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if i < n-1 {
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a[i*lda+i] = bi.Ddot(n-i, a[i*lda+i:], 1, a[i*lda+i:], 1)
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bi.Dgemv(blas.NoTrans, i, n-i-1, 1, a[i+1:], lda, a[i*lda+i+1:], 1,
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aii, a[i:], lda)
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} else {
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bi.Dscal(i+1, aii, a[i:], lda)
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}
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}
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} else {
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// Compute the product L^T*L.
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for i := 0; i < n; i++ {
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aii := a[i*lda+i]
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if i < n-1 {
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a[i*lda+i] = bi.Ddot(n-i, a[i*lda+i:], lda, a[i*lda+i:], lda)
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bi.Dgemv(blas.Trans, n-i-1, i, 1, a[(i+1)*lda:], lda, a[(i+1)*lda+i:], lda,
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aii, a[i*lda:], 1)
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} else {
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bi.Dscal(i+1, aii, a[i*lda:], 1)
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}
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}
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}
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}
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