pub struct AvgAccumulator { /* private fields */ }Expand description
An accumulator to compute the average
Implementations§
Trait Implementations§
source§impl Accumulator for AvgAccumulator
impl Accumulator for AvgAccumulator
source§fn state(&self) -> Result<Vec<AggregateState>>
fn state(&self) -> Result<Vec<AggregateState>>
Returns the state of the accumulator at the end of the accumulation.
in the case of an average on which we track
sum and n, this function should return a vector
of two values, sum and n. Read moresource§fn update_batch(&mut self, values: &[ArrayRef]) -> Result<()>
fn update_batch(&mut self, values: &[ArrayRef]) -> Result<()>
Updates the accumulator’s state from a vector of arrays.
source§fn merge_batch(&mut self, states: &[ArrayRef]) -> Result<()>
fn merge_batch(&mut self, states: &[ArrayRef]) -> Result<()>
updates the accumulator’s state from a vector of states.
source§fn evaluate(&self) -> Result<ScalarValue>
fn evaluate(&self) -> Result<ScalarValue>
returns its value based on its current state.
source§fn size(&self) -> usize
fn size(&self) -> usize
Allocated size required for this accumulator, in bytes, including
Self.
Allocated means that for internal containers such as Vec, the capacity should be used
not the len Read moresource§fn retract_batch(
&mut self,
_values: &[Arc<dyn Array + 'static>]
) -> Result<(), DataFusionError>
fn retract_batch(
&mut self,
_values: &[Arc<dyn Array + 'static>]
) -> Result<(), DataFusionError>
Retracts an update (caused by the given inputs) to accumulator’s state.
Inverse operation of the
update_batch operation. This method must be
for accumulators that should support bounded OVER aggregates. Read more