Files
Aura/crates/aura-std/src/abs.rs
T
Brummel 99237e1d0a feat(std): fill the by-chance vocabulary gaps — Const, Div, Abs, Max, Min
Five new rostered node types (count-pin 23 -> 28, both the in-crate
shape test and the cross-boundary CLI vocabulary e2e): Const is unary
with an f64 'value' param — the clock input drives it, its value is
ignored, since a zero-input node never evaluates in the total-push
engine — mirroring EqConst's constant-as-param pattern; Div is binary
IEEE-754 (x/0 -> signed inf, 0/0 -> NaN, unit-tested, no error
channel); Abs unary mirroring Sqrt; Max/Min binary pairwise, distinct
from the windowed RollingMax/RollingMin.

Acceptance proof: the committed executable spec composes an RSI-class
gain/loss-split-and-ratio signal purely from blueprint data through
std_vocabulary and runs it to hand-computed RS values — the r_meanrev
constant-folding workaround is no longer forced.

Verified: headline test green, aura-std 163/0, full workspace suite
green (independent mini-verify), clippy -D warnings clean.

closes #236
2026-07-10 19:59:10 +02:00

79 lines
2.2 KiB
Rust

//! `Abs` — one-input f64 absolute value. Turns a signed delta (e.g. the
//! negative-side split of a price change) into a positive magnitude, e.g.
//! RSI-class signals' `loss = Abs(Min(delta, 0))`. Emits `None` until its
//! input has a value.
use aura_core::{Cell, Ctx, FieldSpec, Firing, Node, NodeSchema, PortSpec, PrimitiveBuilder, ScalarKind};
/// One-input f64 absolute value, `value.abs()`. Emits `None` until its input
/// has a value (warm-up filter, C8).
pub struct Abs {
out: [Cell; 1],
}
impl Abs {
pub fn new() -> Self {
Self { out: [Cell::from_f64(0.0)] }
}
pub fn builder() -> PrimitiveBuilder {
PrimitiveBuilder::new(
"Abs",
NodeSchema {
inputs: vec![PortSpec { kind: ScalarKind::F64, firing: Firing::Any, name: "value".into() }],
output: vec![FieldSpec { name: "value".into(), kind: ScalarKind::F64 }],
params: vec![],
},
|_| Box::new(Abs::new()),
)
}
}
impl Default for Abs {
fn default() -> Self {
Self::new()
}
}
impl Node for Abs {
fn lookbacks(&self) -> Vec<usize> {
vec![1]
}
fn eval(&mut self, ctx: Ctx<'_>) -> Option<&[Cell]> {
let w = ctx.f64_in(0);
if w.is_empty() {
return None;
}
self.out[0] = Cell::from_f64(w[0].abs());
Some(&self.out)
}
fn label(&self) -> String {
"Abs".to_string()
}
}
#[cfg(test)]
mod tests {
use super::*;
use aura_core::{AnyColumn, Scalar, Timestamp};
#[test]
fn abs_of_negative_and_positive_is_the_magnitude() {
let mut a = Abs::new();
let mut inputs = vec![AnyColumn::with_capacity(ScalarKind::F64, 1)];
inputs[0].push(Scalar::f64(-3.0)).unwrap();
assert_eq!(a.eval(Ctx::new(&inputs, Timestamp(0))), Some([Cell::from_f64(3.0)].as_slice()));
inputs[0].push(Scalar::f64(3.0)).unwrap();
assert_eq!(a.eval(Ctx::new(&inputs, Timestamp(0))), Some([Cell::from_f64(3.0)].as_slice()));
}
#[test]
fn abs_is_none_until_input_present() {
let mut a = Abs::new();
let inputs = vec![AnyColumn::with_capacity(ScalarKind::F64, 1)];
assert_eq!(a.eval(Ctx::new(&inputs, Timestamp(0))), None);
}
}