pub fn exponential(len: usize, scale: f64) -> PdfExpand description
An exponential PDF. scale represents how quickly the PDF decays.
For QSched compatibility, scale can be set to bias·time
J.C.J Barna, E.D Laue, M.R Mayger, J Skilling, S.J.P Worrall, Exponential sampling, an alternative method for sampling in two-dimensional NMR experiments, Journal of Magnetic Resonance (1969), Volume 73, Issue 1, 1987, Pages 69-77, ISSN 0022-2364, https://doi.org/10.1016/0022-2364(87)90225-3.