From aca21d339e81d8b30744a39d34e4fffbd6ddf42e Mon Sep 17 00:00:00 2001
From: Vladimir Chalupecky <vladimir.chalupecky@gmail.com>
Date: Fri, 23 Sep 2016 10:53:54 +0900
Subject: [PATCH] testlapack: add rootsOfUnity help function

---
 testlapack/general.go | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/testlapack/general.go b/testlapack/general.go
index 7479cdea..2f1db614 100644
--- a/testlapack/general.go
+++ b/testlapack/general.go
@@ -1170,3 +1170,13 @@ func isLeftEigenvectorOf(a blas64.General, yRe, yIm []float64, lambda complex128
 	}
 	return true
 }
+
+// rootsOfUnity returns the n complex numbers whose n-th power is equal to 1.
+func rootsOfUnity(n int) []complex128 {
+	w := make([]complex128, n)
+	for i := 0; i < n; i++ {
+		angle := math.Pi * float64(2*i) / float64(n)
+		w[i] = complex(math.Cos(angle), math.Sin(angle))
+	}
+	return w
+}