To be honest, I didn't know myself long either. It is that we learned the Newton-Raphson method with math this year. With that we had to calculate the square root. Now I changed it a bit so it could calculate the log function. I'm not sure though if this is THE way.
A little info:
The Newton-Raphson method is used to calculate the zero value of a function. It calculates the steepness of a function and produces a linear function from that and calculates where this line equals 0. If you keep doing this, you will come closer to the result you want. That means that a recursive function is made with which you can calculate the value. This recursive function looks like this:
Un+1 = Un - f(Un) / f'(Un)
For this you'll need a starting value to work with. This can mostly be like any number, but it's best to choose a number that is closest to the answer. For the log function, I didn't know what that starting value should be, so it's probably not calculated in the normal way.
Now if you want to calculate the log, you need a function which will be zero if x equals the answer. So for 2 log 8, you'll need:
f(x)=2^x-8
This will make the following recursive function:
Un+1 = Un - (2^Un-8) / (2^Un*ln(2))
This would mean you will also need a ln function. That's why I made both.
Maybe this information could be useful to someone, however I don't really think many people are going to use this.
Kevil
