2019-12-20T19:33:23Z Alan Dipert urn:uuid:3e5be466-173c-4159-996f-17326c665756 urn:uuid:d3d294fc-7822-44b3-b2c9-77f1ed34bcbc 2017-10-13T00:00:00Z

R supports recursive functions, but does not optimize tail-recursive functions. Fortunately, with a mechanism known as a trampoline, the R programmer can implement something like the optimization manually and with very little code.

urn:uuid:0e02f8ce-6018-45be-80c0-5cd643b6555a 2018-08-06T00:00:00Z

Transforming trees into tables provides a way to use R like a path query language. The conversion requires walking the tree and storing it in memory as a table, and so may not be suitable for large trees. For small trees, however, the computation time is negligible and the programmer is able to write clear R code for querying the structure without explicitly walking the tree or admitting a separate query language.

urn:uuid:44e90bd4-8702-42a8-b5ce-1c72ae85e46d 2018-12-18T00:00:00Z

Windows 10 can be a productive platform for developing R applications and packages. I show how to install the necessary tools and configure them.

urn:uuid:3c4a9f0a-8f8c-11e9-b4c2-e2eadd5ef15c 2019-06-15T00:00:00Z

Postconditions are assertions about a function’s return value defined within that function. R supports them through a combination of on.exit() and returnValue()

urn:uuid:0ea643de-235b-11ea-8993-000c291e80c7 2019-12-20T00:00:00Z

The markdown package can be used to write inline markdown in a Shiny app’s UI.