blob: 793bb8c7caffdc4e6426258f58e8a59771c5180a [file] [log] [blame]
// 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 "gonum.org/v1/gonum/blas"
// Dlacpy copies the elements of A specified by uplo into B. Uplo can specify
// a triangular portion with blas.Upper or blas.Lower, or can specify all of the
// elements with blas.All.
//
// Dlacpy is an internal routine. It is exported for testing purposes.
func (impl Implementation) Dlacpy(uplo blas.Uplo, m, n int, a []float64, lda int, b []float64, ldb int) {
switch {
case uplo != blas.Upper && uplo != blas.Lower && uplo != blas.All:
panic(badUplo)
case m < 0:
panic(mLT0)
case n < 0:
panic(nLT0)
case lda < max(1, n):
panic(badLdA)
case ldb < max(1, n):
panic(badLdB)
}
if m == 0 || n == 0 {
return
}
switch {
case len(a) < (m-1)*lda+n:
panic(shortA)
case len(b) < (m-1)*ldb+n:
panic(shortB)
}
switch uplo {
case blas.Upper:
for i := 0; i < m; i++ {
for j := i; j < n; j++ {
b[i*ldb+j] = a[i*lda+j]
}
}
case blas.Lower:
for i := 0; i < m; i++ {
for j := 0; j < min(i+1, n); j++ {
b[i*ldb+j] = a[i*lda+j]
}
}
case blas.All:
for i := 0; i < m; i++ {
for j := 0; j < n; j++ {
b[i*ldb+j] = a[i*lda+j]
}
}
}
}