i0e

Modified Bessel function of order zero, exponentially scaled.

SYNOPSIS:

double x, y, i0e();
y = i0e(x);

DESCRIPTION:

Returns exponentially scaled modified Bessel function of order zero of the argument.
The function is defined as i0e(x) = exp(-|x|) j0(ix).

ACCURACY:
                      Relative error:
arithmetic   domain     # trials      peak         rms
    IEEE      0,30        30000       5.4e-16     1.2e-16