Add logLik method to enable AIC() on mkinfit models

Further relax two tests to pass build on Travis

2 files changed, 44 insertions, 1 deletions

diff --git a/man/logLik.mkinfit.Rd b/man/logLik.mkinfit.Rd
new file mode 100644
index 00000000..2f3e58a1
--- /dev/null
+++ b/man/logLik.mkinfit.Rd
@@ -0,0 +1,40 @@
+\name{logLik.mkinfit}
+\alias{logLik.mkinfit}
+\title{
+  Calculated the log-likelihood of a fitted mkinfit object
+}
+\description{
+  This function simply calculates the product of the likelihood densities
+  calc
+}
+\usage{
+\method{logLik}{mkinfit}(object, ...)
+}
+\arguments{
+  \item{object}{
+    An object of class \code{\link{mkinfit}}.
+  }
+  \item{\dots}{
+    For compatibility with the generic method
+  }
+}
+\value{
+  An object of class \code{\link{logLik}} with the number of
+  estimated parameters (degradation model parameters plus variance
+  model parameters) as attribute.
+}
+\examples{
+  sfo_sfo <- mkinmod(
+    parent = mkinsub("SFO", to = "m1"),
+    m1 = mkinsub("SFO")
+  )
+  d_t <- FOCUS_2006_D
+  d_t[23:24, "value"] <- c(NA, NA) # can't cope with zero values at the moment
+  f_nw <- mkinfit(sfo_sfo, d_t, quiet = TRUE)
+  f_obs <- mkinfit(sfo_sfo, d_t, reweight.method = "obs", quiet = TRUE)
+  f_tc <- mkinfit(sfo_sfo, d_t, reweight.method = "tc", quiet = TRUE)
+  AIC(f_nw, f_obs, f_tc)
+}
+\author{
+  Johannes Ranke
+}
diff --git a/man/mkinfit.Rd b/man/mkinfit.Rd
index 00d7eb47..228bab24 100644
--- a/man/mkinfit.Rd
+++ b/man/mkinfit.Rd
@@ -179,7 +179,7 @@ mkinfit(mkinmod, observed,
   \item{weight}{
     only if \code{err}=\code{NULL}: how to weight the residuals, one of "none",
     "std", "mean", see details of \code{\link{modCost}}, or "tc" for the
-    two component error model. The option "manual" is available for 
+    two component error model. The option "manual" is available for
     the case that \code{err}!=\code{NULL}, but it is not necessary to specify it.
   }
   \item{tc}{The two components of the error model as used for (initial)
@@ -245,6 +245,9 @@ mkinfit(mkinmod, observed,
   Plotting methods \code{\link{plot.mkinfit}} and
   \code{\link{mkinparplot}}.
 
+  Comparisons of models fitted to the same data can be made using \code{\link{AIC}}
+  by virtue of the method \code{\link{logLik.mkinfit}}.
+
   Fitting of several models to several datasets in a single call to
   \code{\link{mmkin}}.
 }