github.com/jingcheng-WU/gonum@v0.9.1-0.20210323123734-f1a2a11a8f7b/num/quat/nan.go (about)

     1  // Copyright ©2018 The Gonum Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Copyright 2017 The Go Authors. All rights reserved.
     6  // Use of this source code is governed by a BSD-style
     7  // license that can be found in the LICENSE file.
     8  
     9  package quat
    10  
    11  import "math"
    12  
    13  // IsNaN returns true if any of real(q), imag(q), jmag(q), or kmag(q) is NaN
    14  // and none are an infinity.
    15  func IsNaN(q Number) bool {
    16  	if math.IsInf(q.Real, 0) || math.IsInf(q.Imag, 0) || math.IsInf(q.Jmag, 0) || math.IsInf(q.Kmag, 0) {
    17  		return false
    18  	}
    19  	return math.IsNaN(q.Real) || math.IsNaN(q.Imag) || math.IsNaN(q.Jmag) || math.IsNaN(q.Kmag)
    20  }
    21  
    22  // NaN returns a quaternion ``not-a-number'' value.
    23  func NaN() Number {
    24  	nan := math.NaN()
    25  	return Number{Real: nan, Imag: nan, Jmag: nan, Kmag: nan}
    26  }