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Dot-and-whisker plot of the coefficients of one or more fitted models, terms on the vertical axis and Wald confidence intervals as horizontal segments. Several models are drawn side by side for each term (dodged vertically, with distinct plotting symbols and colours and a legend), so that, for example, pooled, fixed-effects, random-effects and correlated random effects fits of the same specification can be compared in one figure. Every term present in at least one model is shown; a model that does not contain a term has no mark on that row. The left margin is widened to the longest term label so that no label is clipped.

Usage

coefplot(
  ...,
  parm = NULL,
  level = 0.95,
  labels = NULL,
  main = "Coefficient estimates",
  xlab = "Estimate",
  col = NULL,
  pch = NULL,
  ref = 0
)

Arguments

...

fitted models, or a single unclassed list of fitted models. Argument names are used as legend labels.

parm

names or positions (in the order the terms first appear across the models) of the terms to plot; by default every term except "(Intercept)"

level

confidence level of the intervals

labels

legend labels of the models; by default the argument names, or the deparsed arguments

main

plot title

xlab

horizontal-axis label

col

colours of the models, recycled

pch

plotting symbols of the models, recycled

ref

position of the dashed reference line; NULL for none

Value

the models, invisibly, as a named list

Details

Any fitted object with coef() and vcov() methods can be used, e.g. panglm(), paniv(), pangmm(), panfmm() or twopart() fits, and also stats::glm() fits. When vcov() fails or has no entry for a term, only the estimate is drawn.

Examples

data(copd)
f <- exacerbations ~ crp + treatment + age
pool <- panglm(f, data = copd, index = c("id", "visit"),
               model = "pooling", family = "poisson")
re <- panglm(f, data = copd, index = c("id", "visit"),
             model = "random", family = "poisson")
cre <- panglm(f, data = copd, index = c("id", "visit"),
              model = "random", family = "poisson", cre = TRUE)
coefplot(Pooled = pool, RE = re, CRE = cre)