55 lines
2.1 KiB
Rust
55 lines
2.1 KiB
Rust
// Copyright (c) 2012 Leonhard Gruenschloss (leonhard@gruenschloss.org)
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights to
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// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
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// of the Software, and to permit persons to whom the Software is furnished to do
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// so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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// SOFTWARE.
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// Adapted to Rust by Nathan Vegdahl (2017)
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mod matrices;
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pub use matrices::NUM_DIMENSIONS;
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use matrices::{MATRICES, SIZE};
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/// Compute one component of the Sobol'-sequence, where the component
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/// corresponds to the dimension parameter, and the index specifies
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/// the point inside the sequence. The scramble parameter can be used
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/// to permute elementary intervals, and might be chosen randomly to
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/// generate a randomized QMC sequence.
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#[inline]
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pub fn sample_with_scramble(dimension: u32, mut index: u32, scramble: u32) -> f32 {
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assert!((dimension as usize) < NUM_DIMENSIONS);
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let mut result = scramble;
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let mut i = (dimension as usize) * SIZE;
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while index != 0 {
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if (index & 1) != 0 {
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result ^= unsafe { *MATRICES.get_unchecked(i) };
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}
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index >>= 1;
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i += 1;
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}
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return result as f32 * (1.0 / (1u64 << 32) as f32);
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}
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#[inline]
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pub fn sample(dimension: u32, index: u32) -> f32 {
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sample_with_scramble(dimension, index, 0)
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}
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