Crate iter_num_tools

Expand description

§iter-num-tools

This is a collection if iterator extensions that make heavy use of number properties. Mostly extending on Range.

§LinSpace

LinSpace is an iterator over a range with a fixed number of values all evenly spaced.

use iter_num_tools::lin_space;

// Count from 1.0 up to and including 5.0, with 5 numbers counted in total
let it = lin_space(1.0..=5.0, 5);
assert!(it.eq([1.0, 2.0, 3.0, 4.0, 5.0]));

// Count from 0.0 up to and excluding 5.0, with 5 numbers counted in total
let it = lin_space(0.0..5.0, 5);
assert!(it.eq([0.0, 1.0, 2.0, 3.0, 4.0]));

§GridSpace

GridSpace extends on LinSpace.

use iter_num_tools::grid_space;

// count in 2 dimensions (excluding end points),
// from 0.0 up to 1.0 in the x direction with 2 even steps,
// and 0.0 up to 2.0 in the y direction with 4 even steps
let it = grid_space([0.0, 0.0]..[1.0, 2.0], [2, 4]);
assert!(it.eq([
    [0.0, 0.0], [0.5, 0.0],
    [0.0, 0.5], [0.5, 0.5],
    [0.0, 1.0], [0.5, 1.0],
    [0.0, 1.5], [0.5, 1.5],
]));

// count in 2 dimensions (including end points),
// from 0.0 up to 1.0 in the x direction,
// and 0.0 up to 2.0 in the y direction with 3 even steps in all directions
let it = grid_space([0.0, 0.0]..=[1.0, 2.0], 3);
assert!(it.eq([
    [0.0, 0.0], [0.5, 0.0], [1.0, 0.0],
    [0.0, 1.0], [0.5, 1.0], [1.0, 1.0],
    [0.0, 2.0], [0.5, 2.0], [1.0, 2.0],
]));

§Arange

Arange is similar to LinSpace, but instead of a fixed amount of steps, it steps by a fixed amount.

use iter_num_tools::arange;

let it = arange(0.0..2.0, 0.5);
assert!(it.eq([0.0, 0.5, 1.0, 1.5]));

§Note

There is no inclusive version of arange. Consider the following

use iter_num_tools::arange;
let it = arange(0.0..=2.1, 0.5);

We would not expect 2.1 to ever be a value that the iterator will ever meet, but the range suggests it should be included. Therefore, no RangeInclusive implementation is provided.

§ArangeGrid

ArangeGrid is the same as GridSpace but for Arange instead of LinSpace.

use iter_num_tools::arange_grid;

// count in 2 dimensions,
// from 0.0 up to 1.0 in the x direction,
// and 0.0 up to 2.0 in the y direction,
// stepping by 0.5 each time
let it = arange_grid([0.0, 0.0]..[1.0, 2.0], 0.5);
assert!(it.eq([
    [0.0, 0.0], [0.5, 0.0],
    [0.0, 0.5], [0.5, 0.5],
    [0.0, 1.0], [0.5, 1.0],
    [0.0, 1.5], [0.5, 1.5],
]));

// count in 2 dimensions,
// from 0.0 up to 1.0 in the x direction stepping by 0.5 each time,
// and 0.0 up to 2.0 in the y direction stepping by 1.0 each time
let it = arange_grid([0.0, 0.0]..[1.0, 2.0], [0.5, 1.0]);
assert!(it.eq([
    [0.0, 0.0], [0.5, 0.0],
    [0.0, 1.0], [0.5, 1.0],
]));

§LogSpace

LogSpace is similar to LinSpace, but instead of evenly spaced linear steps, it has evenly spaced logarithmic steps.

use iter_num_tools::log_space;
use itertools::zip_eq;

// From 1.0 up to and including 1000.0, taking 4 logarithmic steps
let it = log_space(1.0..=1000.0, 4);
let expected: [f64; 4] = [1.0, 10.0, 100.0, 1000.0];

assert!(zip_eq(it, expected).all(|(x, y)| (x-y).abs() < 1e-10));

// From 1.0 up to 1000.0, taking 3 logarithmic steps
let it = log_space(1.0..1000.0, 3);
let expected: [f64; 3] = [1.0, 10.0, 100.0];

assert!(zip_eq(it, expected).all(|(x, y)| (x-y).abs() < 1e-10));

Traits§

ToArange: Helper trait for arange
ToArangeGrid: Helper trait for arange_grid
ToGridSpace: Helper trait for grid_space
ToGridStep: Helper trait for grid_step
ToLinSpace: A helper trait for lin_space
ToLogSpace: A helper trait for log_space

Functions§

arange: Create a new iterator over the range, stepping by step each time This allows you to create simple float iterators
arange_grid: Creates a grid space over the range made up of fixed step intervals
grid_space: Creates a linear grid space over range with a fixed number of width and height steps
grid_step: Creates a iterator over a range of arrays
lin_space: Creates a linear space over range with a fixed number of steps
log_space: Creates a logarithmic space over range with a fixed number of steps

Type Aliases§

Arange: Iterator returned by arange
ArangeGrid: Iterator returned by arange_grid
GridSpace: Iterator returned by grid_space
GridStep: Iterator returned by [grid_space]
IntoArange: IntoIterator returned by ToArange::into_arange
IntoArangeGrid: IntoIterator returned by [ToGridSpace::into_grid_space]
IntoGridSpace: IntoIterator returned by ToGridSpace::into_grid_space
IntoGridStep: IntoIterator returned by [ToGridSpace::into_grid_space]
IntoLinSpace: IntoIterator returned by ToLinSpace::into_lin_space
IntoLogSpace: IntoIterator returned by ToLogSpace::into_log_space
LinSpace: Iterator returned by lin_space
LogSpace: Iterator returned by log_space

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