grp {irtoys} | R Documentation |
Groups a vector of estimates of the latent variable into a
histogram-like object. Typically invoked by function
itf
, unless the user wishes to access some of the
non-default settings.
grp(theta, bins=9, breaks=NULL, equal="count", type="meds")
theta |
The latent variable estimates to be binned |
bins |
Desired number of bins |
breaks |
A vector of cutpoints. Overrides bins if present. |
equal |
Either "width" for bins of equal width, or "count" for bins with roughly counts of observations. Default is "quant" |
type |
The points at which itf will evaluate the IRF. One of "mids" (the mid-point of each bin), "meds" (the median of the values in the bin), or "means" (the mean of the values in the bin). Default is "meds" . |
A list of:
breaks |
The breaks between adjacent bins |
counts |
The number of values in each bin |
ref |
Depending on ref.type , the mids of the bin, or the mean or median of the values in the bin |
Ivailo Partchev
data(Scored) p.2pl <- est(Scored, model="2PL", engine="ltm") th.mle <- mlebme(resp=Scored, ip=p.2pl) gr <- grp(th.mle, bins=7)