Posts

It is with great pleasure that I can announce that Ryacas version 1.1.0 has now been accepted into Journal of Open Source Software and …

Back in 2017, David Balding and I published the paper “How convincing is a matching Y-chromosome profile?”. One of the key parameters …

In inexact line search (a numerical optimisation technique) the step length (or learning rate) must be decided. In connection to that …

It is with great pleasure that I can announce that Ryacas version 1.0.0 is now released to CRAN …

Update Oct 14, 2019: Michael Höhle caught a mistake and notified me on Twitter. Thanks! The problem is that I used \(\text{Unif}(-10, …

In a recent blog post I tried to get yacas to solve a system of polynomial equations. Unfortunately it could not do that, so I solved …

Finding prediction intervals (for future observations) is something different than finding confidence intervals (for unknown population …

In a recent blog post I used something like this (for use in a call to optim()): obj_fun_expr <- expression((x^4 + 4 * x^2 * y^2 - …

Let \(\rho_{XY}\) be the correlation between the stochastic variables \(X\) and \(Y\) and similarly for \(\rho_{XZ}\) and …

It is important to test software. One approach is unit-testing, and for R packages this can e.g. be done using testthat. It is also …