| // Copyright ©2017 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. |
| |
| //go:build !amd64 || noasm || gccgo || safe |
| // +build !amd64 noasm gccgo safe |
| |
| package f32 |
| |
| // Ger performs the rank-one operation |
| // |
| // A += alpha * x * yᵀ |
| // |
| // where A is an m×n dense matrix, x and y are vectors, and alpha is a scalar. |
| func Ger(m, n uintptr, alpha float32, x []float32, incX uintptr, y []float32, incY uintptr, a []float32, lda uintptr) { |
| |
| if incX == 1 && incY == 1 { |
| x = x[:m] |
| y = y[:n] |
| for i, xv := range x { |
| AxpyUnitary(alpha*xv, y, a[uintptr(i)*lda:uintptr(i)*lda+n]) |
| } |
| return |
| } |
| |
| var ky, kx uintptr |
| if int(incY) < 0 { |
| ky = uintptr(-int(n-1) * int(incY)) |
| } |
| if int(incX) < 0 { |
| kx = uintptr(-int(m-1) * int(incX)) |
| } |
| |
| ix := kx |
| for i := 0; i < int(m); i++ { |
| AxpyInc(alpha*x[ix], y, a[uintptr(i)*lda:uintptr(i)*lda+n], uintptr(n), uintptr(incY), 1, uintptr(ky), 0) |
| ix += incX |
| } |
| } |