log

Returns the logarithm of the number represented in number to the base indicated by base.

An error occurs if either of number or base is not a valid number. The number must be equal to, or greater than 1.

Syntax

   log(number, [base])

Table 1. log parameters
Parameter	Type	Description
number	Decimal number	Any decimal number
base	Decimal number	optional. A number representing the base for which the logarithm will be computed. If no base is supplied, a base of 10 is used.

Returns

A string containing the log of the number to the base, or an empty string if an error occurs.

Example

In this example, the result of log is "2".

   <field sid="logTestField">
      <label>Test log()</label>
      <format>
         <datatype>string</datatype>
         <constraints>
            <mandatory>on</mandatory>
         </constraints>
      </format>
      <value compute="log('100', '10')"></value>
   </field>