Natural logarithm

log x    log[x]

Where x is numeric and

• null, returns null
• 0, returns -0w
• a datetime, returns x
• otherwise, the natural logarithm of x

q)log 1
0f
q)log 0.5
-0.6931472
q)log exp 42
42f
q)log -2 0n 0 0.1 1 42
0n 0n -0w -2.302585 0 3.73767