Logarithm: log

Syntax

log ( op , num )

Input parameters

op	the base of the logarithm
num	the number to which the logarithm is applied

Examples of valid syntaxes

log ( DS_1, 2 )
log ( 1024, 2 )

Semantics for scalar operations

The operator log calculates the logarithm of num base op. For example:

log ( 1024, 2 ) gives 10

log ( 1024, 10 ) gives 3.01

Input parameters type

op

dataset { measure<number [value > 1] > _+ }
| component<number [value > 1] >
| number [value > 1]

num

component<integer [value > 0]>
| integer [value > 0]

Result type

result

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

Additional Constraints

None.

Behavior

As for the invocations at Data Set level, the operator has the behaviour of the “Operators applicable on one Scalar Value or Data Set or Data Set Component”. As for the invocations at Component or Scalar level, the operator has the behaviour of the “Operators applicable on two Scalar Values or Data Sets or Data Set Components”, (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.