Changes in version 2.1.0 (2021-11-20)                  

  - Functions can accomodate polynomial functional forms for the score
    variable w/ or w/o interaction with the treatment variable
  - Improvements to bound constrained optimization (e.g. removed
    two-stage optimization)

                 Changes in version 2.0.0 (2019-08-24)                  

  - Functions can accomodate quadratic functional forms for the score
    variable
  - Users can override default degrees of freedom
  - A few minor changes to naming conventions

                 Changes in version 1.2.2 (2019-05-09)                  

  - Added vectorize.cosa() function, which makes it convenient to run
    and compare multiple designs
  - Removed MMA and COBYLA optimizers from default options

                 Changes in version 1.2.1 (2018-12-16)                  

  - Removed experimental wrapper functions cosa(), mdes() and power()
  - Summaries are printed with the function call
  - Users can specify benchmark values in plots
  - Changed the package title

                 Changes in version 1.2.0 (2018-04-04)                  

  - Added jacobians
  - Option for maximizing power when primary constraint is placed on the
    total cost
  - Bug fixes for cosa.bird2r1() function

                 Changes in version 1.1.0 (2018-03-01)                  

  - Added experimental wrapper functions cosa(), mdes() and power()
  - Added designs with top-level stratification (fixed blocks)
  - Bug fixes for bcrd4r2 and bcrd4r3 designs
  - Added S3 plot() methods
  - Improved validity checks for arguments
  - Added citation