Add dependencies for code generator

vendor/gonum.org/v1/gonum/lapack/gonum/dpotf2.go

@@ -0,0 +1,82 @@
+// 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 gonum
+
+import (
+	"math"
+
+	"gonum.org/v1/gonum/blas"
+	"gonum.org/v1/gonum/blas/blas64"
+)
+
+// Dpotf2 computes the Cholesky decomposition of the symmetric positive definite
+// matrix a. If ul == blas.Upper, then a is stored as an upper-triangular matrix,
+// and a = U^T U is stored in place into a. If ul == blas.Lower, then a = L L^T
+// is computed and stored in-place into a. If a is not positive definite, false
+// is returned. This is the unblocked version of the algorithm.
+//
+// Dpotf2 is an internal routine. It is exported for testing purposes.
+func (Implementation) Dpotf2(ul blas.Uplo, n int, a []float64, lda int) (ok bool) {
+	switch {
+	case ul != blas.Upper && ul != blas.Lower:
+		panic(badUplo)
+	case n < 0:
+		panic(nLT0)
+	case lda < max(1, n):
+		panic(badLdA)
+	}
+
+	// Quick return if possible.
+	if n == 0 {
+		return true
+	}
+
+	if len(a) < (n-1)*lda+n {
+		panic(shortA)
+	}
+
+	bi := blas64.Implementation()
+
+	if ul == blas.Upper {
+		for j := 0; j < n; j++ {
+			ajj := a[j*lda+j]
+			if j != 0 {
+				ajj -= bi.Ddot(j, a[j:], lda, a[j:], lda)
+			}
+			if ajj <= 0 || math.IsNaN(ajj) {
+				a[j*lda+j] = ajj
+				return false
+			}
+			ajj = math.Sqrt(ajj)
+			a[j*lda+j] = ajj
+			if j < n-1 {
+				bi.Dgemv(blas.Trans, j, n-j-1,
+					-1, a[j+1:], lda, a[j:], lda,
+					1, a[j*lda+j+1:], 1)
+				bi.Dscal(n-j-1, 1/ajj, a[j*lda+j+1:], 1)
+			}
+		}
+		return true
+	}
+	for j := 0; j < n; j++ {
+		ajj := a[j*lda+j]
+		if j != 0 {
+			ajj -= bi.Ddot(j, a[j*lda:], 1, a[j*lda:], 1)
+		}
+		if ajj <= 0 || math.IsNaN(ajj) {
+			a[j*lda+j] = ajj
+			return false
+		}
+		ajj = math.Sqrt(ajj)
+		a[j*lda+j] = ajj
+		if j < n-1 {
+			bi.Dgemv(blas.NoTrans, n-j-1, j,
+				-1, a[(j+1)*lda:], lda, a[j*lda:], 1,
+				1, a[(j+1)*lda+j:], lda)
+			bi.Dscal(n-j-1, 1/ajj, a[(j+1)*lda+j:], lda)
+		}
+	}
+	return true
+}