Struct VarianceGroupsAccumulator 

pub struct VarianceGroupsAccumulator { /* private fields */ }

Implementations

impl VarianceGroupsAccumulator

pub fn new(s_type: StatsType) -> Self

pub fn variance(&mut self, emit_to: EmitTo) -> (Vec<f64>, NullBuffer)

Trait Implementations

impl Debug for VarianceGroupsAccumulator

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl GroupsAccumulator for VarianceGroupsAccumulator

fn update_batch( &mut self, values: &[ArrayRef], group_indices: &[usize], opt_filter: Option<&BooleanArray>, total_num_groups: usize, ) -> Result<()>

Updates the accumulator’s state from its arguments, encoded as a vector of ArrayRefs.

fn merge_batch( &mut self, values: &[ArrayRef], group_indices: &[usize], _opt_filter: Option<&BooleanArray>, total_num_groups: usize, ) -> Result<()>

Merges intermediate state (the output from Self::state) into this accumulator’s current state.

fn evaluate(&mut self, emit_to: EmitTo) -> Result<ArrayRef>

Returns the final aggregate value for each group as a single RecordBatch, resetting the internal state.

fn state(&mut self, emit_to: EmitTo) -> Result<Vec<ArrayRef>>

Returns the intermediate aggregate state for this accumulator, used for multi-phase grouping, resetting its internal state.

fn size(&self) -> usize

Amount of memory used to store the state of this accumulator, in bytes.

fn convert_to_state( &self, _values: &[Arc<dyn Array>], _opt_filter: Option<&BooleanArray>, ) -> Result<Vec<Arc<dyn Array>>, DataFusionError>

Converts an input batch directly to the intermediate aggregate state.

fn supports_convert_to_state(&self) -> bool

Returns true if Self::convert_to_state is implemented to support intermediate aggregate state conversion.