| // Copyright ©2016 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 testlapack |
| |
| import ( |
| "fmt" |
| "math" |
| "testing" |
| ) |
| |
| type Dlae2er interface { |
| Dlae2(a, b, c float64) (rt1, rt2 float64) |
| } |
| |
| func Dlae2Test(t *testing.T, impl Dlae2er) { |
| for _, test := range []struct { |
| a, b, c float64 |
| }{ |
| {-10, 5, 3}, |
| {3, 5, -10}, |
| {0, 3, 0}, |
| {1, 3, 1}, |
| {1, -3, 1}, |
| {5, 0, 3}, |
| {3, 0, -5}, |
| {1, 3, 1.02}, |
| {1.02, 3, 1}, |
| {1, -3, -9}, |
| } { |
| a := test.a |
| b := test.b |
| c := test.c |
| rt1, rt2 := impl.Dlae2(a, b, c) |
| |
| errStr := fmt.Sprintf("a = %v, b = %v, c = %v", a, b, c) |
| // Check if rt1 and rt2 are eigenvalues by checking if det(a - λI) = 0 |
| a1 := a - rt1 |
| c1 := c - rt1 |
| det := a1*c1 - b*b |
| if math.Abs(det) > 1e-10 { |
| t.Errorf("First eigenvalue mismatch. %s. Det = %v", errStr, det) |
| } |
| |
| a2 := a - rt2 |
| c2 := c - rt2 |
| det = a2*c2 - b*b |
| if math.Abs(det) > 1e-10 { |
| t.Errorf("Second eigenvalue mismatch. %s. Det = %v", errStr, det) |
| } |
| } |
| } |