Struct SymTensor 

pub struct SymTensor(/* private fields */);

Tensor with symbolic shape and elements.

This is a tensor where the elements and dimension sizes can be either concrete values or symbolic expressions. This type is used during shape inference to represent the shapes of operator inputs and outputs, as well as the values of operations which manipulate shapes.

The symbolic expressions can be integers, symbols with names and assumptions about their values or composite expressions (addition, multiplication etc.)

use rten_shape_inference::{SymTensor, SymExpr};

// Create a matrix with `nr` rows, `nc` columns and unknown values.
let nr = SymExpr::from("nr");
let nc = SymExpr::from("nc");
let matrix = SymTensor::from_shape(vec![nr.clone(), nc.clone()]);
assert_eq!(matrix.ndim(), Some(2));
assert_eq!(matrix.size(0), Some(nr.clone()));
assert_eq!(matrix.size(1), Some(nc.clone()));

// Turn the matrix's shape into a vector with values `["nr", "nc"]`.
let shape = SymTensor::from_vec(matrix.shape().unwrap().collect());
assert_eq!(shape.ndim(), Some(1));
assert_eq!(shape.values(), Some([nr.clone(), nc.clone()].as_slice()));

// Get the number of elements in the matrix as an expression `Some(nr * nc)`.
let len = shape.values().map(|v| v.iter().fold(
    SymExpr::Value(1),
    |prod, dim| prod * dim.clone()
).simplify());
assert_eq!(len, Some(SymExpr::Mul((nr.into(), nc.into()))));

Implementations

impl SymTensor

pub fn unknown(note: &'static str) -> Self

Create a new symbolic tensor with unknown shape and values.

note is a short string indicating the reason why the tensor shape and values are unknown. This is used for debugging purposes.

pub fn from_shape(shape: Vec<SymExpr>) -> Self

Create a new symbolic tensor with the given shape and unknown values.

pub fn from_fixed_shape(shape: &[usize]) -> Self

Create a new symbolic tensor with the given shape and unknown values.

pub fn from_vec(vec: Vec<SymExpr>) -> Self

Create a new symbolic vector.

pub fn from_scalar(item: SymExpr) -> Self

Create a new symbolic scalar.

pub fn as_scalar(&self) -> Option<&SymExpr>

Return this tensor’s single element, if it is a scalar.

pub fn as_vector(&self) -> Option<&[SymExpr]>

Return this tensor’s values as a slice, if it is a vector.

pub fn to_constant(&self) -> Option<Constant>

Return this tensor’s fixed values, if it is a scalar or a vector and all values are fixed.

pub fn ndim(&self) -> Option<usize>

Return the number of dimensions, if known.

pub fn size(&self, index: usize) -> Option<SymExpr>

Return the size of the index’th dimension.

Returns None if the index is out of bounds or the tensor’s shape is unknown.

pub fn shape(&self) -> Option<impl ExactSizeIterator<Item = SymExpr> + Clone>

Return an iterator over the dimensions or None if unknown.

pub fn values(&self) -> Option<&[SymExpr]>

Return the symbolic values in this tensor, or None if unknown.

pub fn simplify(self) -> Self

Simplify symbolic expressions in this tensor.

See SymExpr::simplify.

Trait Implementations

impl Clone for SymTensor

fn clone(&self) -> SymTensor

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SymTensor

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

Formats the value using the given formatter.

impl PartialEq for SymTensor

fn eq(&self, other: &SymTensor) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for SymTensor