Method cdf

Lib/statistics.py:1266–1270

Cumulative distribution function. P(X <= x)

(self, x)

        return exp(diff * diff / (-2.0 * variance)) / sqrt(tau * variance)

    def cdf(self, x):
        "Cumulative distribution function.  P(X <= x)"
        if not self._sigma:
            raise StatisticsError('cdf() not defined when sigma is zero')
        return 0.5 * erfc((self._mu - x) / (self._sigma * _SQRT2))

    def inv_cdf(self, p):
        """Inverse cumulative distribution function.  x : P(X <= x) = p