This function computes the cumulative probability or nonexceedance probability of the Rice distribution given parameters (\(\nu\) and \(\mathrm{SNR}\)) computed by parrice. The cumulative distribution function is complex and numerical integration of the probability density function pdfrice is used.
$$
F(x) = 1 - Q\biggl(\frac{\nu}{\alpha}, \frac{x}{\alpha}\biggr)\mbox{,}
$$
where \(F(x)\) is the nonexceedance probability for quantile \(x\), \(Q(a,b)\) is the Marcum Q-function, and \(\nu/\alpha\) is a form of signal-to-noise ratio \(\mathrm{SNR}\). If \(\nu=0\), then the Rayleigh distribution results and pdfray is used. The Marcum Q-function is difficult to work with and the lmomco uses the integrate function on pdfrice (however, see the Note).