27 lines
1.1 KiB
Markdown
27 lines
1.1 KiB
Markdown
|
# Expressions
|
||
|
|
|
||
|
|
**Experimental: this API is in early stage and could change any time**
|
||
|
|
|
||
|
|
Expressions is an experimental feature which allows to construct 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
|
||
|
|
|
||
|
|
* Maybe symbolic computations (needs additional research)
|
||
|
|
|
||
|
|
The workhorse of this API is `Expression` interface which exposes single `operator fun invoke(arguments: Map<String, T>): T`
|
||
|
|
method. `ExpressionContext` 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 to use full power of `DerivativeStructure`
|
||
|
|
from commons-math. **TODO: add example**
|