Plot the results of the three models used in the NAFTA scheme.

The plots are ordered with increasing complexity of the model in this function (SFO, then IORE, then DFOP).

# S3 method for nafta
plot(x, legend = FALSE, main = "auto", ...)

Arguments

x	An object of class `nafta`.
legend	Should a legend be added?
main	Possibility to override the main title of the plot.
...	Further arguments passed to `plot.mmkin`.

The function is called for its side effect.