slightly modified version of polr from MASS
newpolr(
formula,
data,
weights,
start,
...,
subset,
na.action,
contrasts = NULL,
Hess = FALSE,
model = TRUE,
method = c("logit", "probit", "cloglog", "loglog", "cauchit")
)a formula
an optional data frame, list or environment (or object coercible
by as.data.frame to a data frame) containing the variables in
the model. If not found in data, the variables are taken from
environment(formula), typically the environment from which
cobot is called.
optional case weights in fitting. Default to 1.
initial values for the parameters.
additional arguments to be passed to optim, most
often a control argument.
an optional vector specifying a subset of observations to be used in the fitting process.
a function which indicates what should happen when the data
contain NAs. The default is is na.fail. Another
possible value is NULL, no action. Value na.exclude can
be useful.
a list of contrasts to be used for some or all of the factors appearing as variables in the model formula.
logical for whether the model matrix should be returned.
logistic or probit or complementary log-log, loglog, or cauchit (corresponding to a Cauchy latent variable).
A object of class "polr". This has components
the coefficients of the linear predictor, which has no intercept.
the intercepts for the class boundaries.
the residual deviance.
a matrix, with a column for each level of the response.
the names of the response levels.
the terms structure describing the model.
the number of residual degrees of freedoms, calculated using the weights.
the (effective) number of degrees of freedom used by the model
the (effective) number of observations, calculated using the
weights. (nobs is for use by stepAIC).
the matched call.
the matched method used.
the convergence code returned by optim.
the number of function and gradient evaluations used by
optim.
the linear predictor (including any offset).
(if Hess is true). Note that this is a numerical
approximation derived from the optimization proces.
(if model is true).
polr from MASS