# aggregate\_avg

The function`aggregate_avg(str agg_name, str fieldname)` returns the average of the field  "fieldname" over all documents that passed the relevant filtering.

The aggregation result will be stored under the query results objects, under a key named "`agg_name"`. 

### Input

* <mark style="color:purple;">agg\_name</mark>(str) - Specifies the key that will be used to store the aggregation result under the query result.&#x20;
* <mark style="color:purple;">fieldname</mark>(str) - The name of the field to aggregate. params\[<mark style="color:purple;">fieldname]</mark>must be of type float or int.

**Example:**

```python
def score_function_recommendation( params, doc):
      score = 0.0 
      if match('genres'): 
         aggregate_avg ("avg_budget_genres", "budget")      
         if match('languages'):
             aggregate_avg ("avg_budget", "budget")
         score += rarity_avg('genres')
     return score
```

In the above example, the query results will include a key name 'aggregations', containing the following sub keys:

* **"**<mark style="color:purple;">avg\_budget\_genres</mark>**"** - the average of the field “**budget**” over all candidates that passed the filter over **genres**.
* **"**<mark style="color:purple;">avgg\_budget</mark>**"** - the average of the field “**budget**” over all candidates that passed the filters over **genres** and **languages**.