This field comparator is for numeric fields, where a given maximal
absolute difference can be tolerated. This difference has to be set by
max_abs_diff as a positive value. The default
value is , i.e. no difference is tolerated.
The agreement weight is returned if the numbers are the same, and the
disagreement weight if the absolute difference is larger than the
max_abs_diff value. If the absolute difference between the
two values is larger than but equal to or smaller than
max_abs_diff the partial agreement weight is calculated
according to the following formula.
In its current version no frequency dependent weight calculation is
possible, thus the arguments
can not be used with this field comparator function.