fixed dependencies

vendor/gonum.org/v1/gonum/num/quat/abs.go

@@ -0,0 +1,52 @@
+// 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.
+
+// Copyright 2017 The Go 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 quat
+
+import "math"
+
+// Abs returns the absolute value (also called the modulus) of q.
+func Abs(q Number) float64 {
+	// Special cases.
+	switch {
+	case IsInf(q):
+		return math.Inf(1)
+	case IsNaN(q):
+		return math.NaN()
+	}
+
+	r, i, j, k := q.Real, q.Imag, q.Jmag, q.Kmag
+	if r < 0 {
+		r = -r
+	}
+	if i < 0 {
+		i = -i
+	}
+	if j < 0 {
+		j = -j
+	}
+	if k < 0 {
+		k = -k
+	}
+	if r < i {
+		r, i = i, r
+	}
+	if r < j {
+		r, j = j, r
+	}
+	if r < k {
+		r, k = k, r
+	}
+	if r == 0 {
+		return 0
+	}
+	i /= r
+	j /= r
+	k /= r
+	return r * math.Sqrt(1+i*i+j*j+k*k)
+}