25 lines
1.1 KiB
Markdown
25 lines
1.1 KiB
Markdown
# Expressions
|
|
|
|
Expressions is a feature, which allows constructing lazily or immediately calculated parametric mathematical
|
|
expressions.
|
|
|
|
The potential use-cases for it (so far) are following:
|
|
|
|
* lazy evaluation (in general simple lambda is better, but there are some border cases);
|
|
* automatic differentiation in single-dimension and in multiple dimensions;
|
|
* generation of mathematical syntax trees with subsequent code generation for other languages;
|
|
* symbolic computations, especially differentiation (and some other actions with `kmath-symja` integration with
|
|
Symja's `IExpr`—integration, simplification, and more);
|
|
* visualization with `kmath-jupyter`.
|
|
|
|
The workhorse of this API is `Expression` interface, which exposes
|
|
single `operator fun invoke(arguments: Map<Symbol, T>): T`
|
|
method. `ExpressionAlgebra` is used to generate expressions and introduce variables.
|
|
|
|
Currently there are two implementations:
|
|
|
|
* Generic `ExpressionField` in `kmath-core` which allows construction of custom lazy expressions
|
|
|
|
* Auto-differentiation expression in `kmath-commons` module allows using full power of `DerivativeStructure`
|
|
from commons-math. **TODO: add example**
|