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Changing Logarithm Base
f#

Hello -

Is there an Operator type that allows for the input of any base in a log calculation? I see Operators.log and Operators.log10, however these do not allow me to input my own base.

For example, in C#, I could do:

Math.Log(40, 25);

This represents "Log base 25 of 40", which yields 1.

Thanks!

.

You can just call the .NET API like C#:

> System.Math.Log(40.0, 25.0);;

val it : float = 1.146014837

By on 10/6/2010 11:28 AM ()

Thanks guys! This works.

By on 10/6/2010 11:52 AM ()

remember that for any x, and any b, log_b n = log_x n / log_x b (any x b n where the expression makes sense, that is)

for instance, taking x=e:

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> let logb n b = log n / log b;;

val logb : float -> float -> float

> logb 40. 25.;;

val it : float = 1.146014837
By on 10/6/2010 11:21 AM ()

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