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// Copyright ©2018 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 testblas
import (
"fmt"
"math"
"testing"
"golang.org/x/exp/rand"
"gonum.org/v1/gonum/blas"
)
type Zhbmver interface {
Zhbmv(uplo blas.Uplo, n, k int, alpha complex128, ab []complex128, ldab int, x []complex128, incX int, beta complex128, y []complex128, incY int)
Zhemver
}
func ZhbmvTest(t *testing.T, impl Zhbmver) {
rnd := rand.New(rand.NewSource(1))
for _, uplo := range []blas.Uplo{blas.Upper, blas.Lower} {
for _, n := range []int{0, 1, 2, 3, 5} {
for k := 0; k < n; k++ {
for _, ldab := range []int{k + 1, k + 1 + 10} {
// Generate all possible combinations of given increments.
// Use slices to reduce indentation.
for _, inc := range allPairs([]int{-11, 1, 7}, []int{-3, 1, 5}) {
incX := inc[0]
incY := inc[1]
for _, ab := range []struct {
alpha complex128
beta complex128
}{
// All potentially relevant values of
// alpha and beta.
{0, 0},
{0, 1},
{0, complex(rnd.NormFloat64(), rnd.NormFloat64())},
{complex(rnd.NormFloat64(), rnd.NormFloat64()), 0},
{complex(rnd.NormFloat64(), rnd.NormFloat64()), 1},
{complex(rnd.NormFloat64(), rnd.NormFloat64()), complex(rnd.NormFloat64(), rnd.NormFloat64())},
} {
testZhbmv(t, impl, rnd, uplo, n, k, ab.alpha, ab.beta, ldab, incX, incY)
}
}
}
}
}
}
}
// testZhbmv tests Zhbmv by comparing its output to that of Zhemv.
func testZhbmv(t *testing.T, impl Zhbmver, rnd *rand.Rand, uplo blas.Uplo, n, k int, alpha, beta complex128, ldab, incX, incY int) {
const tol = 1e-13
// Allocate a dense-storage Hermitian band matrix filled with NaNs that will be
// used as the reference matrix for Zhemv.
lda := max(1, n)
a := makeZGeneral(nil, n, n, lda)
// Fill the matrix with zeros.
for i := 0; i < n; i++ {
for j := 0; j < n; j++ {
a[i*lda+j] = 0
}
}
// Fill the triangle band with random data, invalidating the imaginary
// part of diagonal elements because it should not be referenced by
// Zhbmv and Zhemv.
if uplo == blas.Upper {
for i := 0; i < n; i++ {
a[i*lda+i] = complex(rnd.NormFloat64(), math.NaN())
for j := i + 1; j < min(n, i+k+1); j++ {
re := rnd.NormFloat64()
im := rnd.NormFloat64()
a[i*lda+j] = complex(re, im)
}
}
} else {
for i := 0; i < n; i++ {
for j := max(0, i-k); j < i; j++ {
re := rnd.NormFloat64()
im := rnd.NormFloat64()
a[i*lda+j] = complex(re, im)
}
a[i*lda+i] = complex(rnd.NormFloat64(), math.NaN())
}
}
// Create the actual Hermitian band matrix.
ab := zPackTriBand(k, ldab, uplo, n, a, lda)
abCopy := make([]complex128, len(ab))
copy(abCopy, ab)
// Generate a random complex vector x.
xtest := make([]complex128, n)
for i := range xtest {
re := rnd.NormFloat64()
im := rnd.NormFloat64()
xtest[i] = complex(re, im)
}
x := makeZVector(xtest, incX)
xCopy := make([]complex128, len(x))
copy(xCopy, x)
// Generate a random complex vector y.
ytest := make([]complex128, n)
for i := range ytest {
re := rnd.NormFloat64()
im := rnd.NormFloat64()
ytest[i] = complex(re, im)
}
y := makeZVector(ytest, incY)
want := make([]complex128, len(y))
copy(want, y)
// Compute the reference result of alpha*op(A)*x + beta*y, storing it
// into want.
impl.Zhemv(uplo, n, alpha, a, lda, x, incX, beta, want, incY)
// Compute alpha*op(A)*x + beta*y, storing the result in-place into y.
impl.Zhbmv(uplo, n, k, alpha, ab, ldab, x, incX, beta, y, incY)
prefix := fmt.Sprintf("uplo=%v,n=%v,k=%v,incX=%v,incY=%v,ldab=%v", uplo, n, k, incX, incY, ldab)
if !zsame(x, xCopy) {
t.Errorf("%v: unexpected modification of x", prefix)
}
if !zsame(ab, abCopy) {
t.Errorf("%v: unexpected modification of ab", prefix)
}
if !zSameAtNonstrided(y, want, incY) {
t.Errorf("%v: unexpected modification of y", prefix)
}
if !zEqualApproxAtStrided(y, want, incY, tol) {
t.Errorf("%v: unexpected result\nwant %v\ngot %v", prefix, want, y)
}
}