[英]Math.log() is giving me wrong values with c#
I'm having problems using Math.log
in C#, it's giving me wrong values. 我在C#中使用
Math.log
时遇到问题,这给了我错误的值。
In my code: 在我的代码中:
Math.log(0.137931034482758)
returns: -1.98100146886658
返回:
-1.98100146886658
but with a calculator 但是用计算器
log(0.137931034482758)
gives -0.86033800657099
给出
-0.86033800657099
Why is that? 这是为什么?
There seems to a bit of confusion between log(n) and ln(n) where log(n) is really log 10 (n) and ln(n) is the natural logarithm and is equivalent to log e (n) and log(n)和ln(n)之间似乎有些混淆,其中log(n)实际上是log 10 (n),而ln(n)是自然对数,它等效于log e (n)和
So, mathematically 所以,在数学上
log(0.137931034482758) = -0.86033800657099565123053753815789
but 但
ln(0.137931034482758) = -1.9810014688665879083488077894557
Looks like Math.Log uses the natural logarithm. 看起来Math.Log使用自然对数。
If you want log 10 (n) then use Math.Log10(n)
or Math.Log(n, 10)
instead. 如果要记录10 (n),请改用
Math.Log10(n)
或Math.Log(n, 10)
。
As Daisy sais: 正如黛西所说:
log(-1.98100146886658)
with basis e
is -1.98100146886658
基于
e
log(-1.98100146886658)
为-1.98100146886658
log(-1.98100146886658)
with basis 10
is -0.86033800657099
以
10
为-0.86033800657099
log(-1.98100146886658)
是-0.86033800657099
Math.log uses per default e as a basis https://msdn.microsoft.com/de-de/library/x80ywz41(v=vs.110).aspx Math.log默认使用e作为基础https://msdn.microsoft.com/de-de/library/x80ywz41(v=vs.110).aspx
And your calculator obviously uses uses basis 10. 而且您的计算器显然使用使用基准10。
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