Separate the fractional part of a number of the integer part
Does a linear interpolation on the area under the curve of the PDF
of the standard normal between two points. Does the computation in
log-scale so we’re numerically stable in the tails
log-CDF of the standard normal
log-PDF of the standard normal
Returns a numerically stable log(abs(cdf(hi) - cdf(lo)))
for the
standard normal. Should only return log(0.0)
if the bounds are the
same or if the log-PDF at their mid point is f64::NEG_INFINITY
(or
almost).
PDF of the standard normal
Quantile of the standard normal
Quantile-exp (inverse of the log-CDF) of the standard normal