jayzhan211 commented on code in PR #10834: URL: https://github.com/apache/datafusion/pull/10834#discussion_r1632136912
########## datafusion/functions-aggregate/src/stddev.rs: ########## @@ -0,0 +1,380 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +//! Defines physical expressions that can evaluated at runtime during query execution + +use std::any::Any; +use std::fmt::{Debug, Formatter}; + +use arrow::{array::ArrayRef, datatypes::DataType, datatypes::Field}; + +use datafusion_common::{internal_err, not_impl_err, Result}; +use datafusion_common::{plan_err, ScalarValue}; +use datafusion_expr::function::{AccumulatorArgs, StateFieldsArgs}; +use datafusion_expr::utils::format_state_name; +use datafusion_expr::{Accumulator, AggregateUDFImpl, Signature, Volatility}; +use datafusion_physical_expr_common::aggregate::stats::StatsType; + +use crate::variance::VarianceAccumulator; + +make_udaf_expr_and_func!( + Stddev, + stddev, + expression, + "Compute the standard deviation of a set of numbers", + stddev_udaf +); + +/// STDDEV and STDDEV_SAMP (standard deviation) aggregate expression +pub struct Stddev { + signature: Signature, + alias: Vec<String>, +} + +impl Debug for Stddev { + fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result { + f.debug_struct("Stddev") + .field("name", &self.name()) + .field("signature", &self.signature) + .finish() + } +} + +impl Default for Stddev { + fn default() -> Self { + Self::new() + } +} + +impl Stddev { + /// Create a new STDDEV aggregate function + pub fn new() -> Self { + Self { + signature: Signature::numeric(1, Volatility::Immutable), + alias: vec!["stddev_samp".to_string()], + } + } +} + +impl AggregateUDFImpl for Stddev { + /// Return a reference to Any that can be used for downcasting + fn as_any(&self) -> &dyn Any { + self + } + + fn name(&self) -> &str { + "stddev" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn return_type(&self, arg_types: &[DataType]) -> Result<DataType> { + if !arg_types[0].is_numeric() { + return plan_err!("Stddev requires numeric input types"); + } + + Ok(DataType::Float64) + } + + fn state_fields(&self, args: StateFieldsArgs) -> Result<Vec<Field>> { + Ok(vec![ + Field::new( + format_state_name(args.name, "count"), + DataType::UInt64, + true, + ), + Field::new( + format_state_name(args.name, "mean"), + DataType::Float64, + true, + ), + Field::new(format_state_name(args.name, "m2"), DataType::Float64, true), + ]) + } + + fn accumulator(&self, acc_args: AccumulatorArgs) -> Result<Box<dyn Accumulator>> { + if acc_args.is_distinct { + return not_impl_err!("STDDEV_POP(DISTINCT) aggregations are not available"); + } + Ok(Box::new(StddevAccumulator::try_new(StatsType::Sample)?)) + } + + fn create_sliding_accumulator( Review Comment: https://github.com/apache/datafusion/blob/6b7021479c956ba3ca2a04fff81487cd57f80624/datafusion/expr/src/udaf.rs#L414-L419 ########## datafusion/functions-aggregate/src/stddev.rs: ########## @@ -0,0 +1,380 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +//! Defines physical expressions that can evaluated at runtime during query execution + +use std::any::Any; +use std::fmt::{Debug, Formatter}; + +use arrow::{array::ArrayRef, datatypes::DataType, datatypes::Field}; + +use datafusion_common::{internal_err, not_impl_err, Result}; +use datafusion_common::{plan_err, ScalarValue}; +use datafusion_expr::function::{AccumulatorArgs, StateFieldsArgs}; +use datafusion_expr::utils::format_state_name; +use datafusion_expr::{Accumulator, AggregateUDFImpl, Signature, Volatility}; +use datafusion_physical_expr_common::aggregate::stats::StatsType; + +use crate::variance::VarianceAccumulator; + +make_udaf_expr_and_func!( + Stddev, + stddev, + expression, + "Compute the standard deviation of a set of numbers", + stddev_udaf +); + +/// STDDEV and STDDEV_SAMP (standard deviation) aggregate expression +pub struct Stddev { + signature: Signature, + alias: Vec<String>, +} + +impl Debug for Stddev { + fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result { + f.debug_struct("Stddev") + .field("name", &self.name()) + .field("signature", &self.signature) + .finish() + } +} + +impl Default for Stddev { + fn default() -> Self { + Self::new() + } +} + +impl Stddev { + /// Create a new STDDEV aggregate function + pub fn new() -> Self { + Self { + signature: Signature::numeric(1, Volatility::Immutable), + alias: vec!["stddev_samp".to_string()], + } + } +} + +impl AggregateUDFImpl for Stddev { + /// Return a reference to Any that can be used for downcasting + fn as_any(&self) -> &dyn Any { + self + } + + fn name(&self) -> &str { + "stddev" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn return_type(&self, arg_types: &[DataType]) -> Result<DataType> { + if !arg_types[0].is_numeric() { + return plan_err!("Stddev requires numeric input types"); + } + + Ok(DataType::Float64) + } + + fn state_fields(&self, args: StateFieldsArgs) -> Result<Vec<Field>> { + Ok(vec![ + Field::new( + format_state_name(args.name, "count"), + DataType::UInt64, + true, + ), + Field::new( + format_state_name(args.name, "mean"), + DataType::Float64, + true, + ), + Field::new(format_state_name(args.name, "m2"), DataType::Float64, true), + ]) + } + + fn accumulator(&self, acc_args: AccumulatorArgs) -> Result<Box<dyn Accumulator>> { + if acc_args.is_distinct { + return not_impl_err!("STDDEV_POP(DISTINCT) aggregations are not available"); + } + Ok(Box::new(StddevAccumulator::try_new(StatsType::Sample)?)) + } + + fn create_sliding_accumulator( Review Comment: I think we could rely on the default impl, since they are equivalent ########## datafusion/functions-aggregate/src/stddev.rs: ########## @@ -0,0 +1,380 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +//! Defines physical expressions that can evaluated at runtime during query execution + +use std::any::Any; +use std::fmt::{Debug, Formatter}; + +use arrow::{array::ArrayRef, datatypes::DataType, datatypes::Field}; + +use datafusion_common::{internal_err, not_impl_err, Result}; +use datafusion_common::{plan_err, ScalarValue}; +use datafusion_expr::function::{AccumulatorArgs, StateFieldsArgs}; +use datafusion_expr::utils::format_state_name; +use datafusion_expr::{Accumulator, AggregateUDFImpl, Signature, Volatility}; +use datafusion_physical_expr_common::aggregate::stats::StatsType; + +use crate::variance::VarianceAccumulator; + +make_udaf_expr_and_func!( + Stddev, + stddev, + expression, + "Compute the standard deviation of a set of numbers", + stddev_udaf +); + +/// STDDEV and STDDEV_SAMP (standard deviation) aggregate expression +pub struct Stddev { + signature: Signature, + alias: Vec<String>, +} + +impl Debug for Stddev { + fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result { + f.debug_struct("Stddev") + .field("name", &self.name()) + .field("signature", &self.signature) + .finish() + } +} + +impl Default for Stddev { + fn default() -> Self { + Self::new() + } +} + +impl Stddev { + /// Create a new STDDEV aggregate function + pub fn new() -> Self { + Self { + signature: Signature::numeric(1, Volatility::Immutable), + alias: vec!["stddev_samp".to_string()], + } + } +} + +impl AggregateUDFImpl for Stddev { + /// Return a reference to Any that can be used for downcasting + fn as_any(&self) -> &dyn Any { + self + } + + fn name(&self) -> &str { + "stddev" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn return_type(&self, arg_types: &[DataType]) -> Result<DataType> { + if !arg_types[0].is_numeric() { + return plan_err!("Stddev requires numeric input types"); + } + + Ok(DataType::Float64) + } + + fn state_fields(&self, args: StateFieldsArgs) -> Result<Vec<Field>> { + Ok(vec![ + Field::new( + format_state_name(args.name, "count"), + DataType::UInt64, + true, + ), + Field::new( + format_state_name(args.name, "mean"), + DataType::Float64, + true, + ), + Field::new(format_state_name(args.name, "m2"), DataType::Float64, true), + ]) + } + + fn accumulator(&self, acc_args: AccumulatorArgs) -> Result<Box<dyn Accumulator>> { + if acc_args.is_distinct { + return not_impl_err!("STDDEV_POP(DISTINCT) aggregations are not available"); + } + Ok(Box::new(StddevAccumulator::try_new(StatsType::Sample)?)) + } + + fn create_sliding_accumulator( + &self, + args: AccumulatorArgs, + ) -> Result<Box<dyn Accumulator>> { + self.accumulator(args) + } + + fn aliases(&self) -> &[String] { + &self.alias + } +} + +make_udaf_expr_and_func!( + StddevPop, + stddev_pop, + expression, + "Compute the population standard deviation of a set of numbers", + stddev_pop_udaf +); + +/// STDDEV_POP population aggregate expression +pub struct StddevPop { + signature: Signature, +} + +impl Debug for StddevPop { + fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result { + f.debug_struct("StddevPop") + .field("name", &self.name()) + .field("signature", &self.signature) + .finish() + } +} + +impl Default for StddevPop { + fn default() -> Self { + Self::new() + } +} + +impl StddevPop { + /// Create a new STDDEV_POP aggregate function + pub fn new() -> Self { + Self { + signature: Signature::numeric(1, Volatility::Immutable), + } + } +} + +impl AggregateUDFImpl for StddevPop { + /// Return a reference to Any that can be used for downcasting + fn as_any(&self) -> &dyn Any { + self + } + + fn name(&self) -> &str { + "stddev_pop" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn state_fields(&self, args: StateFieldsArgs) -> Result<Vec<Field>> { + Ok(vec![ + Field::new( + format_state_name(args.name, "count"), + DataType::UInt64, + true, + ), + Field::new( + format_state_name(args.name, "mean"), + DataType::Float64, + true, + ), + Field::new(format_state_name(args.name, "m2"), DataType::Float64, true), + ]) + } + + fn accumulator(&self, acc_args: AccumulatorArgs) -> Result<Box<dyn Accumulator>> { + if acc_args.is_distinct { + return not_impl_err!("STDDEV_POP(DISTINCT) aggregations are not available"); + } + Ok(Box::new(StddevAccumulator::try_new(StatsType::Population)?)) + } + + fn create_sliding_accumulator( + &self, + args: AccumulatorArgs, + ) -> Result<Box<dyn Accumulator>> { + self.accumulator(args) Review Comment: same here -- This is an automated message from the Apache Git Service. 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