The standard base-10 logarithm function is supported, generating LOG (expression) and returning a value of type float. When dragging a Logarithm into a variable, the following tree element is created.
Variable Creation > Input > Variables: SQL Elements pane - Arithmetic > Logarithm
Columns and/or other expressions can be moved over the (empty) branch of the tree.
There are no special properties for the Logarithm function.