github.com/jingcheng-WU/gonum@v0.9.1-0.20210323123734-f1a2a11a8f7b/stat/distmv/general.go (about)

     1  // Copyright ©2015 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  package distmv
     6  
     7  const (
     8  	badQuantile      = "distmv: quantile not between 0 and 1"
     9  	badReceiver      = "distmv: input slice is not nil or the correct length"
    10  	badSizeMismatch  = "distmv: size mismatch"
    11  	badZeroDimension = "distmv: zero dimensional input"
    12  	nonPosDimension  = "distmv: non-positive dimension input"
    13  )
    14  
    15  const logTwoPi = 1.8378770664093454835606594728112352797227949472755668
    16  
    17  // useAs gets a slice of size n. If len(x) == n, x is returned, if len(x) == 0
    18  // then a slice is returned of length n.
    19  func reuseAs(x []float64, n int) []float64 {
    20  	if len(x) == n {
    21  		return x
    22  	}
    23  	if len(x) == 0 {
    24  		if cap(x) >= n {
    25  			return x[:n]
    26  		}
    27  		return make([]float64, n)
    28  	}
    29  	panic(badReceiver)
    30  }