1 files changed, 43 insertions, 0 deletions
diff --git a/R/llhist.R b/R/llhist.R
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+#' Plot the distribution of log likelihoods from multistart objects
+#'
+#' Produces a histogram of log-likelihoods. In addition, the likelihood of the
+#' original fit is shown as a red vertical line.
+#'
+#' @param object The [multistart] object
+#' @param breaks Passed to [hist]
+#' @param lpos Positioning of the legend.
+#' @param main Title of the plot
+#' @param \dots Passed to [hist]
+#' @seealso [multistart]
+#' @export
+llhist <- function(object, breaks = "Sturges", lpos = "topleft", main = "",
+  ...)
+{
+  oldpar <- par(no.readonly = TRUE)
+  on.exit(par(oldpar, no.readonly = TRUE))
+
+  if (inherits(object, "multistart.saem.mmkin")) {
+    llfunc <- function(object) {
+      if (inherits(object$so, "try-error")) return(NA)
+      else return(logLik(object$so))
+    }
+  } else {
+    stop("llhist is only implemented for multistart.saem.mmkin objects")
+  }
+
+  ll_orig <- logLik(attr(object, "orig"))
+  ll <- stats::na.omit(sapply(object, llfunc))
+
+  par(las = 1)
+  h <- hist(ll, freq = TRUE,
+    xlab = "", main = main,
+    ylab = "Frequency of log likelihoods", breaks = breaks, ...)
+
+  freq_factor <- h$counts[1] / h$density[1]
+
+  abline(v = ll_orig, col = 2)
+
+  legend(lpos, inset = c(0.05, 0.05), bty = "n",
+    lty = 1, col = c(2),
+    legend = "original fit")
+}