Fit Thurstonian Item Response Theory (IRT) models in R. This 
  package supports fitting Thurstonian IRT models and its extensions using 
  'Stan', 'lavaan', or 'Mplus' for the model estimation. Functionality for 
  extracting results, making predictions, and simulating data is provided as 
  well. References: 
  Brown & Maydeu-Olivares (2011) <doi:10.1177/0013164410375112>;
  Bürkner et al. (2019) <doi:10.1177/0013164419832063>.

Provides a 'tbl_df' class (the 'tibble') with stricter checking and better formatting than the traditional
    data frame.

Built on top of the 'tibble' package, 'tibbletime' is an extension
  that allows for the creation of time aware tibbles. Some immediate
  advantages of this include: the ability to perform time-based subsetting
  on tibbles, quickly summarising and aggregating results by time periods,
  and creating columns that can be used as 'dplyr' time-based groups.

A tool to rectangle a nested list, that is to convert it into
    a tibble. This is done automatically or according to a given
    specification.  A common use case is for nested lists coming from
    parsing JSON files or the JSON response of REST APIs. It is supported
    by the 'vctrs' package and therefore offers a wide support of vector
    types.

Plots and analyzes time-intensity curve data, such as data from 
  (contrast-enhanced) ultrasound. Values such as peak intensity, time to 
  peak, area under the curve, wash in rate and wash out rate are calculated.

This is a small package to provide consistent tick marks for plotting 'ggplot2' figures. 
    It provides breaks and labels for 'ggplot2' without requiring 'ggplot2' to be installed.

Implements tic-tac-toe game to play on console, either with human or AI players.
  Various levels of AI players are trained through the Q-learning algorithm.

Code execution timing functions 'tic' and 'toc' that
    can be nested. One can record all timings while a complex script is
    running, and examine the values later. It is also possible to instrument
    the timing calls with custom callbacks. In addition, this package provides
    class 'Stack', implemented as a vector, and class 'StackList', which is a
    stack implemented as a
    list, both of which support operations 'push', 'pop', 'first_element',
    'last_element' and 'clear'.