Struct AdContext 

pub struct AdContext { /* private fields */ }

Explicit automatic-differentiation context.

AdContext owns the extension AD rules used by traced AD transforms.

Examples

use tenferro_ad::AdContext;

let ad = AdContext::builder().build().unwrap();
assert!(ad.extension_rules().lookup_rule("example.missing.v1").is_none());

Implementations

impl AdContext

pub fn builder() -> AdContextBuilder

Start building an explicit AD context.

Examples

use tenferro_ad::AdContext;

let _builder = AdContext::builder();

pub fn extension_rules(&self) -> &ExtensionRuleSet

Return the extension rules owned by this context.

Examples

use tenferro_ad::AdContext;

let ad = AdContext::builder().build().unwrap();
assert!(!ad.extension_rules().is_rule_registered("example.missing.v1"));

pub fn grad( &self, output: &TracedTensor, wrt: &TracedTensor, ) -> Result<TracedTensor>

Gradient of a scalar traced output with respect to a traced input.

For complex scalar outputs, tenferro returns the Hermitian-adjoint cotangent. To compare seed-1 scalar gradients with JAX’s public grad values, use the complex conjugate of this result. See https://tensor4all.org/tenferro-rs/guides/complex-ad.html.

Examples

use tenferro_ad::AdContext;
use tenferro_runtime::TracedTensor;

let ad = AdContext::builder().build().unwrap();
let x = TracedTensor::from_vec_col_major(vec![], vec![3.0_f64]).unwrap();
let loss = (&x * &x).unwrap();
let grad = ad.grad(&loss, &x).unwrap();
assert_eq!(grad.rank, 0);

pub fn grad_optional( &self, output: &TracedTensor, wrt: &TracedTensor, ) -> Result<Option<TracedTensor>>

Gradient that returns None when wrt is inactive.

Examples

use tenferro_ad::AdContext;
use tenferro_runtime::TracedTensor;

let ad = AdContext::builder().build().unwrap();
let x = TracedTensor::from_vec_col_major(vec![], vec![3.0_f64]).unwrap();
let loss = (&x * &x).unwrap();
assert!(ad.grad_optional(&loss, &x).unwrap().is_some());

pub fn jvp( &self, output: &TracedTensor, wrt: &TracedTensor, tangent: &TracedTensor, ) -> Result<TracedTensor>

Forward-mode Jacobian-vector product.

Examples

use tenferro_ad::AdContext;
use tenferro_runtime::TracedTensor;

let ad = AdContext::builder().build().unwrap();
let x = TracedTensor::from_vec_col_major(vec![], vec![3.0_f64]).unwrap();
let dx = TracedTensor::from_vec_col_major(vec![], vec![1.0_f64]).unwrap();
let y = (&x * &x).unwrap();
let dy = ad.jvp(&y, &x, &dx).unwrap();
assert_eq!(dy.rank, 0);

pub fn jvp_optional( &self, output: &TracedTensor, wrt: &TracedTensor, tangent: &TracedTensor, ) -> Result<Option<TracedTensor>>

Forward-mode Jacobian-vector product that returns None for inactive output.

Examples

use tenferro_ad::AdContext;
use tenferro_runtime::TracedTensor;

let ad = AdContext::builder().build().unwrap();
let x = TracedTensor::from_vec_col_major(vec![], vec![3.0_f64]).unwrap();
let dx = TracedTensor::from_vec_col_major(vec![], vec![1.0_f64]).unwrap();
let y = (&x * &x).unwrap();
assert!(ad.jvp_optional(&y, &x, &dx).unwrap().is_some());

pub fn vjp( &self, output: &TracedTensor, wrt: &TracedTensor, cotangent: &TracedTensor, ) -> Result<TracedTensor>

Reverse-mode vector-Jacobian product.

Complex cotangents use tenferro’s Hermitian real-inner-product convention. Non-real complex cotangent seeds therefore need an explicit seed-convention comparison when matching JAX. See https://tensor4all.org/tenferro-rs/guides/complex-ad.html.

Examples

use tenferro_ad::AdContext;
use tenferro_runtime::TracedTensor;

let ad = AdContext::builder().build().unwrap();
let x = TracedTensor::from_vec_col_major(vec![], vec![3.0_f64]).unwrap();
let dy = TracedTensor::from_vec_col_major(vec![], vec![1.0_f64]).unwrap();
let y = (&x * &x).unwrap();
let dx = ad.vjp(&y, &x, &dy).unwrap();
assert_eq!(dx.rank, 0);

pub fn vjp_optional( &self, output: &TracedTensor, wrt: &TracedTensor, cotangent: &TracedTensor, ) -> Result<Option<TracedTensor>>

Reverse-mode vector-Jacobian product that returns None for inactive input.

Examples

use tenferro_ad::AdContext;
use tenferro_runtime::TracedTensor;

let ad = AdContext::builder().build().unwrap();
let x = TracedTensor::from_vec_col_major(vec![], vec![3.0_f64]).unwrap();
let dy = TracedTensor::from_vec_col_major(vec![], vec![1.0_f64]).unwrap();
let y = (&x * &x).unwrap();
assert!(ad.vjp_optional(&y, &x, &dy).unwrap().is_some());

Trait Implementations

impl Clone for AdContext

fn clone(&self) -> AdContext

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AdContext

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

Formats the value using the given formatter.