Activity Relation Field
In the API you may wish to filter pharmacology data for points with values greater or less than a cut-off you require. You will notice that there are fields in the API for "activity_relation" and also "min/max/minEx/maxEx-activity_value".
You should use the "min/max/minEx/maxEx-activity_value" fields to filter pharmacology by activity values.
The "activity_relation" field comes from the pharmacology data. For instance, ChEMBL uses a set of 4 values to define an activity data point: activity type (e.g. IC50) , relation (=), value (a number) and unit (e.g. nM) .
The "activity_relation" field represents the ">", "=" etc part of the data that was recorded in the source database.
For example, min-activity_value=10 could return a datapoint recorded as "IC50 < 20nM". Because the min-activity_value is used to actually perform the filtering but returns any pharmacology regardless of the 'activity_relation' setting.
To discard such activities one can set: min-activity_value=10&activity_relation=>=|>|=
(Taking care to URL encode all but the first '=' char for the activity relation param)