function logcdf( x, mu, s ) {
	var z;
	if (
		isnan( x ) ||
		isnan( mu ) ||
		isnan( s ) ||
		s < 0.0
	) {
		return NaN;
	}
	if ( s === 0.0 ) {
		return ( x < mu ) ? NINF : 0.0;
	}
	if ( x < mu - s ) {
		return NINF;
	}
	if ( x > mu + s ) {
		return 0.0;
	}
	z = ( x - mu ) / s;
	return ln( ( 1.0 + z + ( sinpi( z ) / PI ) ) / 2.0 );
}
Evaluates the natural logarithm of the cumulative distribution function (CDF) for a raised cosine distribution with location parameter `mu` and scale parameter `s` at a value `x`.

@param {number} x - input value
@param {number} mu - location parameter
@param {NonNegativeNumber} s - scale parameter
@returns {number} evaluated logCDF

@example
var y = logcdf( 0.5, 0.0, 1.0 );
// returns ~-0.095

@example
var y = logcdf( 1.2, 0.0, 1.0 );
// returns 0.0

@example
var y = logcdf( -0.9, 0.0, 1.0 );
// returns ~-7.108

@example
var y = logcdf( 2.0, 0.0, NaN );
// returns NaN

@example
var y = logcdf( 2.0, NaN, 1.0 );
// returns NaN

@example
var y = logcdf( NaN, 0.0, 1.0 );
// returns NaN