ramp_exponential()

MAYAFLUX_API std::vector< double > MayaFlux::Kinesis::Discrete::ramp_exponential	(	size_t	n,
		double	start = 0.001,
		double	end = 1.0
	)

Exponential ramp from start to end over n samples.

Each step multiplies by a constant growth factor. A true exponential cannot originate at zero, so start is clamped away from it; callers wanting a curve that begins at silence should offset the result.

Parameters

n	Length in samples
start	First value, clamped to magnitude >= 1e-9
end	Last value

Returns

Vector of length n; n == 1 returns { start }

Definition at line 253 of file Transform.cpp.

{
    if (n == 0)
        return {};
 
    constexpr double k_min_magnitude = 1e-9;
    double s = start;
    if (std::abs(s) < k_min_magnitude)
        s = std::copysign(k_min_magnitude, s == 0.0 ? 1.0 : s);
 
    if (n == 1)
        return { s };
 
    double e = end;
    if (std::abs(e) < k_min_magnitude)
        e = std::copysign(k_min_magnitude, e == 0.0 ? 1.0 : e);
    if ((s < 0.0) != (e < 0.0))
        e = std::copysign(std::abs(e), s);
 
    std::vector<double> out(n);
    const double growth = std::pow(e / s, 1.0 / static_cast<double>(n - 1));
    out[0] = s;
    for (size_t i = 1; i < n; ++i)
        out[i] = out[i - 1] * growth;
    return out;
}