Struct HistogramAccumulator 

pub struct HistogramAccumulator { /* private fields */ }

An accumulator for computing histograms.

Implementations

impl HistogramAccumulator

pub fn new(start: f64, end: f64, nb_bins: usize) -> HistogramAccumulator

pub fn new_non_configured() -> HistogramAccumulator

pub fn configure_from_params( &mut self, start: f64, end: f64, nb_bins: i64, ) -> Result<(), DataFusionError>

Validates and sets histogram bounds from scalar parameters.

pub fn configure( &mut self, histo_array: &HistogramArray, ) -> Result<(), DataFusionError>

If not configured, scans for the first non-null row and uses it as a template. If already configured or if all rows are null, does nothing.

pub fn update_batch_scalars( &mut self, scalars: &PrimitiveArray<Float64Type>, ) -> Result<(), DataFusionError>

pub fn merge_histograms( &mut self, histo_array: &HistogramArray, ) -> Result<(), DataFusionError>

Trait Implementations

impl Accumulator for HistogramAccumulator

fn update_batch( &mut self, values: &[Arc<dyn Array>], ) -> Result<(), DataFusionError>

Updates the accumulator’s state from its input.

fn evaluate(&mut self) -> Result<ScalarValue, DataFusionError>

Returns the final aggregate value.

fn size(&self) -> usize

Returns the allocated size required for this accumulator, in bytes, including Self.

fn state(&mut self) -> Result<Vec<ScalarValue>, DataFusionError>

Returns the intermediate state of the accumulator, consuming the intermediate state.

fn merge_batch( &mut self, states: &[Arc<dyn Array>], ) -> Result<(), DataFusionError>

Updates the accumulator’s state from an Array containing one or more intermediate values.

fn retract_batch( &mut self, _values: &[Arc<dyn Array>], ) -> Result<(), DataFusionError>

Retracts (removed) an update (caused by the given inputs) to accumulator’s state.

fn supports_retract_batch(&self) -> bool

Does the accumulator support incrementally updating its value by removing values.

impl Debug for HistogramAccumulator

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

Formats the value using the given formatter.