link.con {plink} | R Documentation |
These functions extract information from an object of class irt.pars
,
typically created using plink
, or an object of
class irt.prob
containing expected probabilities.
link.con(x, method = "ALL") link.pars(x) link.ability(x) get.prob(x)
x |
an R object |
method |
character vector identifying the linking methods for which
constants should be returned. The only acceptable values are
ALL, MM, MS, HB, SL, and RM . See below for details. |
link.con
extracts the linking constants,
link.pars
extracts the rescaled item parameters (if present), and
link.ability
extracts the rescaled ability estimates (if present)
get.prob
extracts expected probabilities for an irt.prob
object
For link.con
, the following values can be included for method
.
For multidimensional constants, although matrices A
, K
, and T
are
included in the object of class "link
" for the Haebara and Stocking-Lord
methods, only the matrix A
will be returned for these methods.
MM
:MS
:HB
:SL
:RM
:Returns a matrix or list of linking constants
Jonathan P. Weeks weeksjp@gmail.com