Files
nushell/crates/nu-cmd-dataframe/src/dataframe/expressions/quantile.rs
Ian Manske c747ec75c9 Add command_prelude module (#12291)
# Description
When implementing a `Command`, one must also import all the types
present in the function signatures for `Command`. This makes it so that
we often import the same set of types in each command implementation
file. E.g., something like this:
```rust
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
    record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, PipelineData,
    ShellError, Signature, Span, Type, Value,
};
```

This PR adds the `nu_engine::command_prelude` module which contains the
necessary and commonly used types to implement a `Command`:
```rust
// command_prelude.rs
pub use crate::CallExt;
pub use nu_protocol::{
    ast::{Call, CellPath},
    engine::{Command, EngineState, Stack},
    record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, IntoSpanned,
    PipelineData, Record, ShellError, Signature, Span, Spanned, SyntaxShape, Type, Value,
};
```

This should reduce the boilerplate needed to implement a command and
also gives us a place to track the breadth of the `Command` API. I tried
to be conservative with what went into the prelude modules, since it
might be hard/annoying to remove items from the prelude in the future.
Let me know if something should be included or excluded.
2024-03-26 21:17:30 +00:00

102 lines
2.9 KiB
Rust

use crate::dataframe::values::{Column, NuDataFrame, NuExpression};
use nu_engine::command_prelude::*;
use polars::prelude::{lit, QuantileInterpolOptions};
#[derive(Clone)]
pub struct ExprQuantile;
impl Command for ExprQuantile {
fn name(&self) -> &str {
"dfr quantile"
}
fn usage(&self) -> &str {
"Aggregates the columns to the selected quantile."
}
fn signature(&self) -> Signature {
Signature::build(self.name())
.required(
"quantile",
SyntaxShape::Number,
"quantile value for quantile operation",
)
.input_output_type(
Type::Custom("expression".into()),
Type::Custom("expression".into()),
)
.category(Category::Custom("expression".into()))
}
fn examples(&self) -> Vec<Example> {
vec![Example {
description: "Quantile aggregation for a group-by",
example: r#"[[a b]; [one 2] [one 4] [two 1]]
| dfr into-df
| dfr group-by a
| dfr agg (dfr col b | dfr quantile 0.5)"#,
result: Some(
NuDataFrame::try_from_columns(
vec![
Column::new(
"a".to_string(),
vec![Value::test_string("one"), Value::test_string("two")],
),
Column::new(
"b".to_string(),
vec![Value::test_float(4.0), Value::test_float(1.0)],
),
],
None,
)
.expect("simple df for test should not fail")
.into_value(Span::test_data()),
),
}]
}
fn search_terms(&self) -> Vec<&str> {
vec!["statistics", "percentile", "distribution"]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let value = input.into_value(call.head);
let quantile: f64 = call.req(engine_state, stack, 0)?;
let expr = NuExpression::try_from_value(value)?;
let expr: NuExpression = expr
.into_polars()
.quantile(lit(quantile), QuantileInterpolOptions::default())
.into();
Ok(PipelineData::Value(
NuExpression::into_value(expr, call.head),
None,
))
}
}
#[cfg(test)]
mod test {
use super::super::super::test_dataframe::test_dataframe;
use super::*;
use crate::dataframe::lazy::aggregate::LazyAggregate;
use crate::dataframe::lazy::groupby::ToLazyGroupBy;
#[test]
fn test_examples() {
test_dataframe(vec![
Box::new(ExprQuantile {}),
Box::new(LazyAggregate {}),
Box::new(ToLazyGroupBy {}),
])
}
}