mean
Computes the mean (average) of values.
null
values are ignored.
All primitive numeric types are supported: Byte
, Short
, Int
, Long
, Float
, and Double
.
mean
also supports the "mixed" Number
type, as long as the column consists only of the aforementioned primitive numbers. The numbers are automatically converted to a common type for the operation.
The return type is always Double
; Double.NaN
for empty columns.
All operations on Double
/Float
/Number
have the skipNaN
option, which is set to false
by default. This means that if a NaN
is present in the input, it will be propagated to the result. When it's set to true
, NaN
values are ignored.
See statistics for details on complex data aggregations.
Type Conversion
The following automatic type conversions are performed for the mean
operation:
Conversion | Result for Empty Input |
---|---|
Int -> Double | Double.NaN |
Byte -> Double | Double.NaN |
Short -> Double | Double.NaN |
Long -> Double | Double.NaN |
Double -> Double | Double.NaN |
Float -> Double | Double.NaN |
Number -> Conversion(Common number type) -> Double | Double.NaN |
Nothing -> Double | Double.NaN |