gitee.com/quant1x/num@v0.3.2/math32/nextafter.go (about)

     1  // Copyright 2010 The Go 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  package math32
     6  
     7  // Nextafter returns the next representable float32 value after x towards y.
     8  //
     9  // Special cases are:
    10  //
    11  //	Nextafter32(x, x)   = x
    12  //	Nextafter32(NaN, y) = NaN
    13  //	Nextafter32(x, NaN) = NaN
    14  func Nextafter(x, y float32) (r float32) {
    15  	switch {
    16  	case IsNaN(x) || IsNaN(y): // special case
    17  		r = float32(NaN())
    18  	case x == y:
    19  		r = x
    20  	case x == 0:
    21  		r = float32(Copysign(Float32frombits(1), y))
    22  	case (y > x) == (x > 0):
    23  		r = Float32frombits(Float32bits(x) + 1)
    24  	default:
    25  		r = Float32frombits(Float32bits(x) - 1)
    26  	}
    27  	return
    28  }