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Diffstat (limited to 'pl/math/tools/asinh.sollya')
-rw-r--r-- | pl/math/tools/asinh.sollya | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/pl/math/tools/asinh.sollya b/pl/math/tools/asinh.sollya new file mode 100644 index 0000000..663ee92 --- /dev/null +++ b/pl/math/tools/asinh.sollya @@ -0,0 +1,28 @@ +// polynomial for approximating asinh(x) +// +// Copyright (c) 2022-2023, Arm Limited. +// SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception + +// Polynomial is used in [2^-26, 1]. However it is least accurate close to 1, so +// we use 2^-6 as the lower bound for coeff generation, which yields sufficiently +// accurate results in [2^-26, 2^-6]. +a = 0x1p-6; +b = 1.0; + +f = (asinh(sqrt(x)) - sqrt(x))/x^(3/2); + +approx = proc(poly, d) { + return remez(1 - poly(x)/f(x), deg-d, [a;b], x^d/f(x), 1e-10); +}; + +poly = 0; +for i from 0 to deg do { + i; + p = roundcoefficients(approx(poly,i), [|D ...|]); + poly = poly + x^i*coeff(p,0); +}; + + +display = hexadecimal; +print("coeffs:"); +for i from 0 to deg do coeff(poly,i); |