logarithm function

[janvda]

jsonata provides the $power() function.
It would be interesting if it would also provide a logarithm function.

This new function could be named $log() and has an optional 2nd parameter representing the base. If the base is not specified then it uses 10 as base.

[janvda]

Just looked at which built-in javascript functions exist.

So it would be sufficient if one of the following 2 functions is exposed:

• Math.log()
• Math.log10()

[jngothia]

I would like a log() function as well.