LlLog

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Summary

Function: float llLog( float val );

Returns a float that is the natural logarithm of val.
If val <= 0 return 0.0 instead.

• float val

To get the base 10 logarithm use llLog10.

Examples

default
{
  state_entry()
  {
    float num1 = llFrand(100.0);
 
    llOwnerSay("The natural logarithm of " + (string)num1 + " is " + (string)llLog(num1));
  }
}
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 log functions llLog and llLog10. Errors introduced as a result of floating-point arithmetic are most noticable when working with logarithms. llLog should be used instead of llLog10 when converting the base of the logarithm.

float LogBaseN = llLog(value) / llLog(Base); //This technique introduces errors but is the only way

If Base is a constant, your script will run faster if you calculate it's log and divide by that constant instead.


Useful natural logarithms
Number logarithm
2 0.69314718056
4 1.38629436112
8 2.07944154168
10 2.30258509299
16 2.77258872224
32 3.4657359028
64 4.15888308336
128 4.85203026392
256 5.54517744448

See Also

Functions

•  llLog10
•  llPow
•  llSqrt

Articles

•  Wikipedia:Natural logarithm

Deep Notes

Search JIRA for related Issues

Signature

function float llLog( float val );