/rust/registry/src/index.crates.io-1949cf8c6b5b557f/pic-scale-safe-0.1.12/src/math/lagrange.rs

Source
/*
 * Copyright (c) Radzivon Bartoshyk, 10/2024. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1.  Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 2.  Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3.  Neither the name of the copyright holder nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

use num_traits::AsPrimitive;
use std::ops::{Add, Div, Mul, MulAssign, Sub};

#[inline(always)]
pub(crate) fn lagrange<
    V: Copy
        + PartialEq
        + PartialOrd
        + AsPrimitive<usize>
        + Mul<Output = V>
        + Add<Output = V>
        + Sub<Output = V>
        + Div<Output = V>
        + MulAssign,
>(
    x: V,
    support: usize,
) -> V
where
    f32: AsPrimitive<V>,
    usize: AsPrimitive<V>,
{
    if x > support.as_() {
        return 0f32.as_();
    }
    let order = (2.0f32.as_() * support.as_()).as_();
    let n = (support.as_() + x).as_();
    let mut value = 1.0f32.as_();
    for i in 0..order {
        if i != n {
            value *= (n.as_() - i.as_() - x) / (n.as_() - i.as_());
        }
    }
    value
}

#[inline(always)]
pub(crate) fn lagrange2<
    V: Copy
        + PartialEq
        + PartialOrd
        + AsPrimitive<usize>
        + Mul<Output = V>
        + Add<Output = V>
        + Sub<Output = V>
        + Div<Output = V>
        + MulAssign,
>(
    x: V,
) -> V
where
    f32: AsPrimitive<V>,
    usize: AsPrimitive<V>,
{
    lagrange(x, 2)
}

#[inline(always)]
pub(crate) fn lagrange3<
    V: Copy
        + PartialEq
        + PartialOrd
        + AsPrimitive<usize>
        + Mul<Output = V>
        + Add<Output = V>
        + Sub<Output = V>
        + Div<Output = V>
        + MulAssign,
>(
    x: V,
) -> V
where
    f32: AsPrimitive<V>,
    usize: AsPrimitive<V>,
{
    lagrange(x, 3)
}

Coverage Report

Created: 2026-09-28 07:57

Line	Count	Source
1		/*
2		* Copyright (c) Radzivon Bartoshyk, 10/2024. All rights reserved.
3		*
4		* Redistribution and use in source and binary forms, with or without modification,
5		* are permitted provided that the following conditions are met:
6		*
7		* 1. Redistributions of source code must retain the above copyright notice, this
8		* list of conditions and the following disclaimer.
9		*
10		* 2. Redistributions in binary form must reproduce the above copyright notice,
11		* this list of conditions and the following disclaimer in the documentation
12		* and/or other materials provided with the distribution.
13		*
14		* 3. Neither the name of the copyright holder nor the names of its
15		* contributors may be used to endorse or promote products derived from
16		* this software without specific prior written permission.
17		*
18		* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19		* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20		* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21		* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
22		* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23		* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24		* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
25		* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26		* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27		* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28		*/
29
30		use num_traits::AsPrimitive;
31		use std::ops::{Add, Div, Mul, MulAssign, Sub};
32
33		#[inline(always)]
34	0	pub(crate) fn lagrange<
35	0	V: Copy
36	0	+ PartialEq
37	0	+ PartialOrd
38	0	+ AsPrimitive<usize>
39	0	+ Mul<Output = V>
40	0	+ Add<Output = V>
41	0	+ Sub<Output = V>
42	0	+ Div<Output = V>
43	0	+ MulAssign,
44	0	>(
45	0	x: V,
46	0	support: usize,
47	0	) -> V
48	0	where
49	0	f32: AsPrimitive<V>,
50	0	usize: AsPrimitive<V>,
51		{
52	0	if x > support.as_() {
53	0	return 0f32.as_();
54	0	}
55	0	let order = (2.0f32.as_() * support.as_()).as_();
56	0	let n = (support.as_() + x).as_();
57	0	let mut value = 1.0f32.as_();
58	0	for i in 0..order {
59	0	if i != n {
60	0	value *= (n.as_() - i.as_() - x) / (n.as_() - i.as_());
61	0	}
62		}
63	0	value
64	0	}
65
66		#[inline(always)]
67	0	pub(crate) fn lagrange2<
68	0	V: Copy
69	0	+ PartialEq
70	0	+ PartialOrd
71	0	+ AsPrimitive<usize>
72	0	+ Mul<Output = V>
73	0	+ Add<Output = V>
74	0	+ Sub<Output = V>
75	0	+ Div<Output = V>
76	0	+ MulAssign,
77	0	>(
78	0	x: V,
79	0	) -> V
80	0	where
81	0	f32: AsPrimitive<V>,
82	0	usize: AsPrimitive<V>,
83		{
84	0	lagrange(x, 2)
85	0	}
86
87		#[inline(always)]
88	0	pub(crate) fn lagrange3<
89	0	V: Copy
90	0	+ PartialEq
91	0	+ PartialOrd
92	0	+ AsPrimitive<usize>
93	0	+ Mul<Output = V>
94	0	+ Add<Output = V>
95	0	+ Sub<Output = V>
96	0	+ Div<Output = V>
97	0	+ MulAssign,
98	0	>(
99	0	x: V,
100	0	) -> V
101	0	where
102	0	f32: AsPrimitive<V>,
103	0	usize: AsPrimitive<V>,
104		{
105	0	lagrange(x, 3)
106	0	}