[](https://crates.io/crates/softposit)
[](https://crates.io/crates/softposit)
## `softposit-rs`
Rust port of [SoftPosit] repository.
[SoftPosit]: https://gitlab.com/cerlane/SoftPosit
Such types are supported now:
* P32E2 or P32: 32-bit posit with exponent size ES=2;
* P16E1 or P16: 16-bit posit with ES=1;
* P8E0 or P8: 8-bit posit without exponent bits.
Initial suppot of generic types PxE1{N} and PxE2{N}.
Requires nightly rustc and `nightly` feature to be enabled.
## Examples
### Convert from f64, Add
```
use softposit::P32;
fn main() {
let a = P32::from(12.3);
let b = P32::from(154.);
let c = a + b;
println!("c = {0} or c = {0:?}", c);
}
```
## Quire
Each Posit type has correspondent Quire type (Q32, Q16, Q8).
These types support `AddAssign` and `SubAssign` operations.
For example:
```
use softposit::{P32, Q32};
// c == 12.3*0.4 - 6.3*8.4 == -48;
fn main() {
let mut q = Q32::init();
q += (P32::from(12.3), P32::from(0.4));
q -= (P32::from(6.3), P32::from(8.4));
let c = q.to_posit();
println!("c = {0} or c = {0:?}", c);
}
```
## Math
Math functions, like trigonomentic, are partially implemented for P32E2 type.
For complex computations use `num::Complex` type.
## Linear algebra
You can also use matrix operations, defined in [nalgebra](https://crates.io/crates/nalgebra) crate
by using `linalg` feature:
```
use softposit::P32;
use nalgebra::{Dynamic, Matrix, VecStorage};
type DMatrix = Matrix<P32, Dynamic, Dynamic, VecStorage<P32, Dynamic, Dynamic>>;
fn main() {
let a = DMatrix::new_random(5, 5);
println!("Matrix A = {}", a);
let decomp = &a.clone().lu();
if let Some(c) = decomp.try_inverse() {
println!("Inverse matrix Aˉ¹ = {}", c);
println!("Check Identity");
let ones = a * c;
println!("A × Aˉ¹ = {}", ones);
} else {
println!("Matrix A can't be inverted");
}
}
```
```
cargo build --features="linalg,rand"
```
## Benchmarking
```
cargo bench
```
| P32E2 | + | 47 MPOPS | 82 MPOPS |
| | - | 45 MPOPS | 83 MPOPS |
| | * | 56 MPOPS | 99 MPOPS |
| | / | 25 MPOPS | 42 MPOPS |
| | √⎺⎺ | 48 MPOPS | 92 MPOPS |
| | round | 89 MPOPS | 159 MPOPS |