i0Modified Bessel function of order zero.
double x, y, i0();
y = i0(x);
Returns a modified Bessel function of order zero of the argument.
The function is defined as i0(x) = j0(ix).
The range is partitioned into the two intervals [0,8] and (8, infinity). Chebyshev polynomial expansions are employed in each interval.
arithmetic domain # trials peak rms
DEC 0,30 6000 8.2e-17 1.9e-17
IEEE 0,30 30000 5.8e-16 1.4e-16