Crate micromath

Embedded-friendly (i.e. #![no_std]) math library featuring fast, safe floating point approximations for common arithmetic operations, as well as 2D and 3D vector types, statistical analysis functions, and quaternions.

Floating point approximations: F32 and F32Ext

micromath supports approximating many arithmetic operations on f32 using bitwise operations, providing great performance and small code size at the cost of precision. For use cases like graphics and signal processing, these approximations are often sufficient and the performance gains worth the lost precision.

These approximations are defined on the F32 newtype wrapper.

F32Ext extension trait

Floating point approximations can used via the the F32Ext trait which is impl’d for f32, providing a drop-in std-compatible API.

use micromath::F32Ext;

let n = 2.0.sqrt();
assert_eq!(n, 1.5); // close enough

Since the F32Ext trait provides methods which are already defined in std, in cases where your crate links std the F32Ext versions of the same methods will not be used, in which case you will get an unused import warning for F32Ext.

If you encounter this, add an #[allow(unused_imports)] above the import.

#[allow(unused_imports)]
use micromath::F32Ext;

Vector types

See the vector module for more information on vector types.

The following vector types are available, all of which have pub x and pub y (and on 3D vectors, pub z) members:

Rust	2D	3D
i8	I8x2	I8x3
i16	I16x2	I16x3
i32	I32x2	I32x3
u8	U8x2	U8x3
u16	U16x2	U16x3
u32	U32x2	U32x3
f32	F32x2	F32x3

Statistical analysis

See the statistics module for more information on statistical analysis traits and functionality.

The following traits are available and impl’d for slices and iterators of f32 (and can be impl’d for other types):

• Mean - compute arithmetic mean with the mean() method.
• StdDev - compute standard deviation with the stddev() method.
• Trim - cull outliers from a sample slice with the trim() method.
• Variance - compute variance with the variance() method.

Re-exports

• pub use num_traits;

Modules

• statisticsstatistics
  Statistical analysis support.
• vectorvector
  Algebraic vector types generic over a component type.

Structs

• F32
  32-bit floating point wrapper which implements fast approximation-based operations.
• Quaternionquaternion
  Quaternions are a number system that extends the complex numbers which can be used for efficiently computing spatial rotations.

Traits

• F32Ext
  f32 extension providing various arithmetic approximations and polyfills for std functionality.