How do I make an NPC to calculate a logarithm?

[Freyr]

How do I make an NPC to calculate a logarithm?

for example:

 set @tax,log10(Zeny) * 10;

Edited October 18, 2015 by Freyr

[Haziel]

If I recall correctly, a logarithm is the calculation about which exponent a base must be raised to reach a value.
If I also recall correctly, there is not a in-built function which calculates that, so, you need a Custom Function.

I made this one:

prontera,150,150,3	script	Test#log	420,{
	mes "" + callfunc("Logarithim",10,10000) + "";
	close;
}
	
function	script	Logarithim	{
	set @basis, getarg(0);
	set @value, getarg(1);
	
	set @m, @basis;
	for (set @n, 2; @m < @value; set @n, @n + 1){
		for (set @o, 1; @o < @n; set @o, @o + 1){
			set @m, @m * @basis;	
		}
		if (@m == @value)
			return @n;
		else if (@m > @value)
			return (@n - 1);
		else 
			set @m, @basis;
	}
	return 0;
}

It's just a scratch and I don't know if it works perfectly.

By the way, you can enter an basis and a target value, it will returns either the correct Logarithim or the closest one.

Edited October 18, 2015 by Haziel

[Ninja]

set @tax,log10(Zeny) * 10;
 

Function script logarthm {
Set .@base, getarg(0);
Set .@targetnum, getarg(1);
Set .@x1, 1;
For(set .@x,0:.@x<=.@targetnum;set .@x, .@x +1) {
Set .@x1, .@x1 * .@base;
}

Return .@x*10;
}

Usage: set @tax, callfunc("logarthm",basenum,targetnum);

Sample simulation:

Log2(8)
.@x       0    1    2    3
.@x1     1    2    4    8

Returns 3

Check:
2 ^ 3 = 8


You can do it this way since, in my knowledge, everything ingame works with an integer.

Edited October 19, 2015 by jezznar