New in 0.2.2

Fixed the name of the vignette in the vignette index entry!

New in 0.2.1

Nothing, really, except that I had to provide new links to the ICL files as a result of Dropbox's new policy on shared files. God bless Brad's beautiful soul, 15 years dead and still helping us.

New in 0.2.0

* Added functions to estimate and plot the interaction model

* Added erf, a function to plot the empirical item response function

* Added ssm, a function to produce IRF in the sum score metric

* Added ifp, a function to plot IRF with error bounds. 

* Small improvements in the tia function

* Links to download Brad Hanson's ICL program (see the package help page)

			      CHANGES IN irtoys VERSION 0.1.7
NEW FEATURES

  o new function, tet(), to calculate, quickly,  an approximate matrix of
    tetrachoric correlations. 

BUG FIXES

  o fixed a bug in function wle() which affected the variance of Warm's 
    weighted estimate of ability in the case of the 3PL model only.
