llLog

float llLog(float Value)

Returns the natural logarithm of Value. Returns zero if Value <= 0.

Returns the base e (natural) logarithm of the specified Value.

Parameters

Value (float)

Technical Details

Return Type: float
Energy: 10

Basic usage to calculate natural logarithm:

default
{
  state_entry()
  {
    float num1 = llFrand(100.0);

    llOwnerSay("The natural logarithm of " + (string)num1 + " is " + (string)llLog(num1));
  }
}

Converting to arbitrary logarithm base:

float findexp(float result, float base)
{
    return llLog(result)/llLog(base);
}

default
{
    touch_start(integer total_number)
    {
        llSay(0, (string)findexp(8.0, 2.0));
        // returns 3.0
    }
}

Notes

There are only two logarithm functions: llLog and llLog10. When converting the base of the logarithm, use llLog rather than llLog10 as it introduces fewer errors. The general formula for converting to an arbitrary base is:

float LogBaseN = llLog(value) / llLog(Base);

Note that this technique inherently introduces errors due to floating-point arithmetic, which are most noticeable when working with logarithms. If the base is a constant, your script will run faster if you pre-calculate its logarithm and divide by that constant instead.

Useful Natural Logarithm Values

Number	ln(Number)
2	0.693147
4	1.386294
8	2.079442
10	2.302585
16	2.772589
32	3.465736
64	4.158883
128	4.852030
256	5.545177

llLog

Notes

Useful Natural Logarithm Values

See Also