| // Copyright 2009 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 math |
| |
| // Log10 returns the decimal logarithm of x. |
| // The special cases are the same as for Log. |
| |
| //extern log10 |
| func libc_log10(float64) float64 |
| |
| func Log10(x float64) float64 { |
| return libc_log10(x) |
| } |
| |
| func log10(x float64) float64 { |
| return Log(x) * (1 / Ln10) |
| } |
| |
| // Log2 returns the binary logarithm of x. |
| // The special cases are the same as for Log. |
| |
| func Log2(x float64) float64 { |
| return log2(x) |
| } |
| |
| func log2(x float64) float64 { |
| frac, exp := Frexp(x) |
| return Log(frac)*(1/Ln2) + float64(exp) |
| } |
