% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/radial.R
\name{radial.brma}
\alias{radial.brma}
\alias{radial}
\alias{galbraith}
\alias{galbraith.brma}
\title{Radial (Galbraith) Plot for brma Object}
\usage{
\method{radial}{brma}(
  x,
  center = FALSE,
  xlim,
  zlim,
  xlab,
  zlab,
  atz,
  aty,
  steps = 7,
  level = 95,
  digits = 2,
  transf,
  targs,
  plot_type = "base",
  ...
)

\method{galbraith}{brma}(x, ...)
}
\arguments{
\item{x}{a fitted brma object. Must be an intercept-only model
(no moderators or scale regression).}

\item{center}{logical indicating whether to center the plot at the
pooled estimate. When \code{TRUE}, the pooled estimate is shifted to
zero on the z-axis. Defaults to \code{FALSE}.}

\item{xlim}{x-axis limits. If not specified, limits are computed from data.}

\item{zlim}{z-axis limits. If not specified, limits are computed from data.}

\item{xlab}{title for the x-axis. If not specified, a default label is used.}

\item{zlab}{title for the z-axis. If not specified, a default label is used.}

\item{atz}{numeric vector of positions for tick marks on the z-axis (left
vertical axis). If not specified, positions are chosen automatically.}

\item{aty}{numeric vector of effect size values to mark on the y-axis arc
(right side). If not specified, values are chosen automatically.}

\item{steps}{integer specifying the number of tick marks on the y-axis arc
when \code{aty} is not specified. Defaults to \code{7}.}

\item{level}{numeric value between 0 and 100 specifying the confidence level
for the confidence band and pooled-effect CI arc. Defaults to \code{95}.}

\item{digits}{integer specifying the number of decimal places for y-axis
arc labels. Defaults to \code{2}.}

\item{transf}{optional transformation function applied to the y-axis arc
labels (e.g., \code{transf = exp} when effect sizes are on a log scale).}

\item{targs}{optional list of additional arguments passed to the
\code{transf} function.}

\item{plot_type}{whether to use a base plot \code{"base"} or ggplot2
\code{"ggplot"} for plotting. Defaults to \code{"base"}.}

\item{...}{additional graphical arguments to customize the plot appearance:
\describe{
\item{pch}{point symbol (default: 21, filled circle)}
\item{col}{point border color (default: "black")}
\item{bg}{point fill/background color (default: "#A6A6A6")}
\item{cex}{point size multiplier for base graphics (default: 1)}
\item{size}{point size for ggplot2 (default: 2)}
\item{las}{axis-label style for base graphics (default: 1)}
\item{back}{background color for the confidence band (default: "grey90").
Set to \code{NA} to suppress.}
\item{arc.res}{integer specifying the number of line segments used to
draw arcs (default: 100)}
\item{main}{character string for plot title (default: no title)}
\item{as_data}{if \code{TRUE}, returns plot data instead of creating
the plot}
}}
}
\value{
\code{radial.brma} returns \code{NULL} invisibly if
\code{plot_type = "base"} or a ggplot object if \code{plot_type = "ggplot"}.

If \code{as_data = TRUE}, returns a list with the computed plot data
including: \code{points}, \code{refline}, \code{band}, \code{arc},
\code{arc_ticks}, \code{ci_arc}, \code{ci_ticks}, \code{xlim}, and
\code{zlim}.
}
\description{
\code{radial.brma} creates a radial (Galbraith) plot for a
fitted brma object. The plot displays each study as a point with
precision on the x-axis and the standardized effect size on the z-axis.
Without centering, a line from the origin through any point has slope equal
to the observed effect size. With centering, slopes are relative to the
pooled estimate. An arc on the right side maps standardized values back to
the effect size scale.
}
\details{
The radial (Galbraith) plot transforms each study's effect size and
standard error into a point in precision-standardized space:

\itemize{
\item x-axis: precision = \eqn{1/\sqrt{v_i + \hat{\tau}^2}}
\item z-axis: standardized effect = \eqn{y_i/\sqrt{v_i + \hat{\tau}^2}}
}

Under the random-effects model, studies consistent with the pooled effect
should fall within the sloped parallelogram confidence band around the
pooled-effect line. The arc on the right side allows reading individual
effect sizes by projecting from the origin through a point to the arc; when
\code{center = TRUE}, the plotted slope is relative to the pooled effect.

This function requires an intercept-only model; radial plots are not
meaningful for meta-regression or location-scale models where the
pooled effect varies across studies.

\code{galbraith()} is a same-argument alias for \code{radial()}.
}
\examples{
\dontrun{
if (requireNamespace("metadat", quietly = TRUE) &&
    requireNamespace("metafor", quietly = TRUE)) {
  data(dat.bcg, package = "metadat")
  dat <- metafor::escalc(
    measure = "RR",
    ai      = tpos,
    bi      = tneg,
    ci      = cpos,
    di      = cneg,
    data    = dat.bcg
  )

  fit <- brma(yi = yi, vi = vi, data = dat, measure = "RR")
  radial(fit)
  radial(fit, center = TRUE)
  radial(fit, plot_type = "ggplot")
  galbraith(fit)
}
}

}
\references{
Galbraith, R. F. (1988). Graphical display of estimates having differing
standard errors. \emph{Technometrics}, 30(3), 271-281.

Galbraith, R. F. (1994). Some applications of radial plots. \emph{Journal
of the American Statistical Association}, 89(428), 1232-1242.
}
\seealso{
\code{\link[=funnel.brma]{funnel.brma()}}, \code{\link[=pooled_effect.brma]{pooled_effect.brma()}}, \code{\link[=pooled_heterogeneity.brma]{pooled_heterogeneity.brma()}}
}
