Categories:

Aggregate Functions (Linear Regression) , Window Functions

# REGR_AVGX¶

Returns the average of the independent variable for non-null pairs in a group, where `x` is the independent variable and `y` is the dependent variable.

## Syntax¶

Aggregate function

```REGR_AVGX(y, x)
```

Window function

```REGR_AVGX(y, x) OVER ( [ PARTITION BY <expr3> ] )
```

## Arguments¶

`y`

The dependent variable. This must be an expression that can be evaluated to a numeric type.

`x`

The independent variable. This must be an expression that can be evaluated to a numeric type.

`expr3`

This is the optional expression used to group rows into partitions.

Important

Note the order of the arguments; the dependent variable is first.

## Usage Notes¶

• DISTINCT is not supported for this function.

• In order for a row to be included in the average, BOTH the x and y values must be non-NULL.

• When used as a window function:

• This function does not support:

• ORDER BY sub-clause in the OVER() clause.

• Window frames.

## Examples¶

```CREATE OR REPLACE TABLE aggr(k int, v decimal(10,2), v2 decimal(10, 2));
INSERT INTO aggr VALUES(1, 10, NULL);
INSERT INTO aggr VALUES(2, 10, 11), (2, 20, 22), (2, 25, NULL), (2, 30, 35);
```
```SELECT k, REGR_AVGX(v, v2) FROM aggr GROUP BY k;

---+------------------+
k | regr_avgx(v, v2) |
---+------------------+
1 | [NULL]           |
2 | 22.666666667     |
---+------------------+
``` 