The computation of the cumulative distribution (cdf), the complementar
y cdf (ccdf), and the density of certain shot-noise random variables i
s discussed. After subtracting off a few terms that can be computed in
closed form, what remains can be approximated by a general method for
approximating samples of a cdf or ccdf by summing a Fourier series wh
ose coefficients are modulated samples of their characteristic functio
n. To approximate the density, a spline is fit to the cdf samples and
then differentiated. When the density has corners, it is important tha
t the spline have coincident knots at these locations. For shot-noise
densities, these locations are easily identified.