% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/wordfish.R
\name{initialize.urfish}
\alias{initialize.urfish}
\title{initialize.urfish}
\usage{
initialize.urfish(tY)
}
\arguments{
\item{tY}{a document by word matrix of counts}
}
\value{
List with elements: \item{alpha}{starting values of alpha
parameters} \item{psi}{starting values of psi parameters}
\item{beta}{starting values of beta parameters} \item{theta}{starting values
for document positions}
}
\description{
Get cheap starting values for a Wordfish model
}
\details{
This function is only called by model fitting routines and does therefore
not take a wfm classes.  tY is assumed to be in document by term form.

In the poisson form of the model incidental parameters (alpha) are set to
log(rowmeans/rowmeans[1]).  intercept (psi) values are set to log(colmeans)
These are subtracted from a the data matrix, which is logged and decomposed
by SVD.  Word slope (beta) and document position (theta) are estimated by
rescaling SVD output.
}
\references{
This is substantially the method used by Slapin and Proksch's
original code.
}
\author{
Will Lowe
}
