exponential-integral 0.2.3

//! Relevant internal constants. Not user-facing.

#![expect(
    clippy::excessive_precision,
    clippy::unreadable_literal,
    reason = "copy & paste"
)]

/// Known sizes of constant arrays.
pub(crate) mod size {
    /// AE11
    pub(crate) const AE11: usize = 39;
    /// AE12
    pub(crate) const AE12: usize = 25;
    /// AE13
    pub(crate) const AE13: usize = 25;
    /// AE14
    pub(crate) const AE14: usize = 26;
    /// E11
    pub(crate) const E11: usize = 19;
    /// E12
    pub(crate) const E12: usize = 16;
}

/// AE11
pub(crate) const AE11: [f64; size::AE11] = [
    0.121503239716065790,
    -0.065088778513550150,
    0.004897651357459670,
    -0.000649237843027216,
    0.000093840434587471,
    0.000000420236380882,
    -0.000008113374735904,
    0.000002804247688663,
    0.000000056487164441,
    -0.000000344809174450,
    0.000000058209273578,
    0.000000038711426349,
    -0.000000012453235014,
    -0.000000005118504888,
    0.000000002148771527,
    0.000000000868459898,
    -0.000000000343650105,
    -0.000000000179796603,
    0.000000000047442060,
    0.000000000040423282,
    -0.000000000003543928,
    -0.000000000008853444,
    -0.000000000000960151,
    0.000000000001692921,
    0.000000000000607990,
    -0.000000000000224338,
    -0.000000000000200327,
    -0.000000000000006246,
    0.000000000000045571,
    0.000000000000016383,
    -0.000000000000005561,
    -0.000000000000006074,
    -0.000000000000000862,
    0.000000000000001223,
    0.000000000000000716,
    -0.000000000000000024,
    -0.000000000000000201,
    -0.000000000000000082,
    0.000000000000000017,
];

/// AE12
pub(crate) const AE12: [f64; size::AE12] = [
    0.582417495134726740,
    -0.158348850905782750,
    -0.006764275590323141,
    0.005125843950185725,
    0.000435232492169391,
    -0.000143613366305483,
    -0.000041801320556301,
    -0.000002713395758640,
    0.000001151381913647,
    0.000000420650022012,
    0.000000066581901391,
    0.000000000662143777,
    -0.000000002844104870,
    -0.000000000940724197,
    -0.000000000177476602,
    -0.000000000015830222,
    0.000000000002905732,
    0.000000000001769356,
    0.000000000000492735,
    0.000000000000093709,
    0.000000000000010707,
    -0.000000000000000537,
    -0.000000000000000716,
    -0.000000000000000244,
    -0.000000000000000058,
];

/// AE13
pub(crate) const AE13: [f64; size::AE13] = [
    -0.605773246640603460,
    -0.112535243483660900,
    0.013432266247902779,
    -0.001926845187381145,
    0.000309118337720603,
    -0.000053564132129618,
    0.000009827812880247,
    -0.000001885368984916,
    0.000000374943193568,
    -0.000000076823455870,
    0.000000016143270567,
    -0.000000003466802211,
    0.000000000758754209,
    -0.000000000168864333,
    0.000000000038145706,
    -0.000000000008733026,
    0.000000000002023672,
    -0.000000000000474132,
    0.000000000000112211,
    -0.000000000000026804,
    0.000000000000006457,
    -0.000000000000001568,
    0.000000000000000383,
    -0.000000000000000094,
    0.000000000000000023,
];

/// AE14
pub(crate) const AE14: [f64; size::AE14] = [
    -0.18929180007530170,
    -0.08648117855259871,
    0.00722410154374659,
    -0.00080975594575573,
    0.00010999134432661,
    -0.00001717332998937,
    0.00000298562751447,
    -0.00000056596491457,
    0.00000011526808397,
    -0.00000002495030440,
    0.00000000569232420,
    -0.00000000135995766,
    0.00000000033846628,
    -0.00000000008737853,
    0.00000000002331588,
    -0.00000000000641148,
    0.00000000000181224,
    -0.00000000000052538,
    0.00000000000015592,
    -0.00000000000004729,
    0.00000000000001463,
    -0.00000000000000461,
    0.00000000000000148,
    -0.00000000000000048,
    0.00000000000000016,
    -0.00000000000000005,
];

/// E11
pub(crate) const E11: [f64; size::E11] = [
    -16.11346165557149402600,
    7.79407277874268027690,
    -1.95540581886314195070,
    0.37337293866277945612,
    -0.05692503191092901938,
    0.00721107776966009185,
    -0.00078104901449841593,
    0.00007388093356262168,
    -0.00000620286187580820,
    0.00000046816002303176,
    -0.00000003209288853329,
    0.00000000201519974874,
    -0.00000000011673686816,
    0.00000000000627627066,
    -0.00000000000031481541,
    0.00000000000001479904,
    -0.00000000000000065457,
    0.00000000000000002733,
    -0.00000000000000000108,
];

/// E12
pub(crate) const E12: [f64; size::E12] = [
    -0.03739021479220279500,
    0.04272398606220957700,
    -0.13031820798497005440,
    0.01441912402469889073,
    -0.00134617078051068022,
    0.00010731029253063780,
    -0.00000742999951611943,
    0.00000045377325690753,
    -0.00000002476417211390,
    0.00000000122076581374,
    -0.00000000005485141480,
    0.00000000000226362142,
    -0.00000000000008635897,
    0.00000000000000306291,
    -0.00000000000000010148,
    0.00000000000000000315,
];

/*
pub(crate) const AE11_F: &[Finite<f64>; size::AE11] = {
    let ptr: *const [f64; size::AE11] = &AE11;
    let cast: *const [Finite<f64>; size::AE11] = ptr.cast();
    // SAFETY:
    // `Finite<..>` is `repr(transparent)`
    unsafe { &*cast }
};
*/

#[cfg(feature = "error")]
/// I'd guess that this is the maximum (average?) error between adjacent `f64` values.
pub(crate) const GSL_DBL_EPSILON: f64 = 2.220_446_049_250_313_1e-16;

// pub(crate) const XMAXT: f64 = 708.396_418_532_264_08;

/// No original C code: equal to `-XMAX`.
/// See `XMAX` for its original C code.
pub(crate) const NXMAX: f64 = -XMAX;

/// # Original C code
/// ```c
/// const double XMAX = XMAXT - f64::ln(XMAXT);
/// ```
pub(crate) const XMAX: f64 = 701.833_414_682_1; // XMAXT - f64::ln(XMAXT);