~~NOTOC~~
<=[[4rpl:start| Index]] \\
<= [[4rpl:start#Math]]  

====== ln ======
LN

===== Description =====
The natural logarithm. Gives the magnitude of the number. On zero, returns -inf. Below zero, returns NaN, a special value that always causes failure when compared to other numbers. Eg. (NaN<0) -> false, (Nan>=0) -> false

other logarithms
<WRAP indent>
ln(x) = log(x, e) \\ 
ln(x)/ln(10) = log10(x) \\ 
ln(2)=0.6931… \\ 
ln(e)=.999999 \\ 
ln(10)=2.3026… 
</WRAP>

===== Examples =====
<code 4rpl>
trace(ln(-1)) #prints 'NaN'
trace(ln(0))  #prints '-inf'
trace(ln(1))  #prints '0'
trace(ln(e))  #prints '1'
</code>
<=[[4rpl:start| Index]]