0f97c0b05b
新增 TLUSTY 模块: - crossd: 光电离截面评估 (bound-free cross section) - sgmer0: 合并能级光电离截面初始化 - sgmerd: 合并能级光电离截面计算 - dwnfr0: 频率网格下载 (continuum) - convc1: 对流收敛控制 (radiative) - chckse: 统计平衡检查 (rates) 扩展 RESOLV 编排器: - 添加 Feautrier 形式解 - 添加 Lucy 温度修正 - 添加 ROSSTD/PZEVAL/CONOUT 调用 - 添加 IFPOPR=2 占据数更新 - 添加 HESOL6 流体静力平衡修正 修复: - sgmer0.rs: 修复 config 未声明为 mut 的编译错误 - crossd.rs: 修复测试中使用错误字段路径的问题 (frqall.ijbf/phoexp.aijbf/phoexp.bfcs 而非 obfpar) Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
78 lines
1.8 KiB
Rust
78 lines
1.8 KiB
Rust
//! 二分查找子程序。
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//!
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//! 重构自 SYNSPEC `locate.f`
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//!
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//! 在有序数组 `xx` 中查找值 `x` 的位置，使得 `xx[j] <= x < xx[j+1]`。
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/// 在有序数组中二分查找。
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///
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/// 查找 `x` 在有序数组 `xx[0..n]` 中的插入位置。
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/// 返回索引 `j`，使得 `xx[j-1] <= x < xx[j]`（1-indexed）。
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///
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/// # 参数
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///
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/// * `xx` - 有序数组（升序或降序）
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/// * `n` - 数组有效长度
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/// * `x` - 待查找的值
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///
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/// # 返回值
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///
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/// 索引 `j`（1-indexed），使得 `xx[j-1] <= x < xx[j]`
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pub fn locate(xx: &[f64], n: usize, x: f64) -> usize {
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let mut jl: isize = 0;
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let mut ju = (n + 1) as isize;
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while ju - jl > 1 {
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let jm = (ju + jl) / 2;
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if (xx[n - 1] >= xx[0]) == (x >= xx[jm as usize - 1]) {
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jl = jm;
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} else {
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ju = jm;
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}
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}
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if x == xx[0] {
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1
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} else if x == xx[n - 1] {
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n - 1
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} else {
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jl as usize
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}
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn test_locate_basic() {
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let xx = [1.0, 2.0, 3.0, 4.0, 5.0];
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// x=2.5 应该在 xx[1] 和 xx[2] 之间，返回 j=2
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let j = locate(&xx, 5, 2.5);
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assert!(j >= 1 && j <= 4);
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assert!(xx[j - 1] <= 2.5 && xx[j] >= 2.5);
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}
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#[test]
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fn test_locate_exact_first() {
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let xx = [1.0, 2.0, 3.0, 4.0, 5.0];
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let j = locate(&xx, 5, 1.0);
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assert_eq!(j, 1);
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}
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#[test]
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fn test_locate_exact_last() {
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let xx = [1.0, 2.0, 3.0, 4.0, 5.0];
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let j = locate(&xx, 5, 5.0);
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assert_eq!(j, 4);
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}
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#[test]
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fn test_locate_between() {
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let xx = [0.0, 10.0, 20.0, 30.0];
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let j = locate(&xx, 4, 15.0);
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assert!(j >= 1 && j <= 3);
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assert!(xx[j - 1] <= 15.0 && xx[j] >= 15.0);
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}
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}
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