LlLog
From Second Life Wiki
Revision as of 11:19, 22 January 2015 by ObviousAltIsObvious Resident (Talk | contribs)
LSL Portal | Functions | Events | Types | Operators | Constants | Flow Control | Script Library | Categorized Library | Tutorials |
Summary
Function: float llLog( float val );265 | Function ID |
0.0 | Forced Delay |
10.0 | Energy |
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.
Caveats
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.
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 |