Natural logarithm: ln

Syntax

ln ( op )

Input parameters

op	the operand

Examples of valid syntaxes

ln ( DS_1 )
ln ( 148 )

Semantics for scalar operations

The operator ln calculates the natural logarithm of a number. For example:

ln ( 148 ) gives 4.997...
ln ( e ) gives 1.0
ln ( 1 ) gives 0.0
ln ( 0.5 ) gives -0.693...

Input parameters type

op

dataset { measure<number [value > 0] > _+ }
| component<number [value > 0] >
| number [value > 0]

Result type

result

dataset { measure<number> _+ }
| component<number>
| number

Additional Constraints

None.

Behaviour

The operator has the behaviour of the “Operators applicable on one Scalar Value or Data Set or Data Set Component” (see the section “Typical behaviours of the ML Operators”). According to the general rules about data types, the operator can be applied also on sub-types of number, that is the type integer. The result has type number.