2013-05-25  V_0.1-1 Youyi Fong

    * create package

2013-08-14  V_0.1-2 Youyi Fong

    * add set.seed(1) to chngpt.score.test so that the results are
    reproducible
    * rename chngpt.score.test to chngpt.test
    * MASS is used for generating reference distribution samples while mvrnorm
    is used in sim.sigmoid. In principle, should be able to use a single
    package, but since the simulation studies for the paper has already been
    run, just leave it as it is
    * let search.all.thresholds be true if n < 500

2015-09-01  Youyi Fong

    * when glm warns, set the log likelihood to NA

2015-09-29  Youyi Fong

    * implement more vcov
    * add e.effective.maxit to deal with non-convergence
    
2015-10-18  Youyi Fong

    * when est.method==smoothapprox, effective chgnpt needs to be determined
    to stop infinite loops. It used to be defined in between two observed data
    values, but is not set to one observed data value

2015-11-19  Youyi Fong

    * make.chngpt.var now takes b. as an argument, the results of smoothapprox
    estimation will change!

2016-01-24  Youyi Fong

    * add testing for linear model

2017-05-13  Youyi Fong

    * modify make.chngpt.var to fit smooth transition model
    * add sandwich variance estimator
    * add segmented2
    * change b to -b

2017-09-16  Youyi Fong

    * this version contains some commented out code related to indices, which
    was used to compare with R implemention
    
2017-10-27  Youyi Fong

    * a major cleanup of sim.chngpt
	* weighted estimation now works
