Get min/max values
Details
Returns list with minimum and maximum values of several model runs for better
plotting. The list includes the range for i) bg_biommass, ii) ag_biomass,
iii) nutrients_pool, and iv) detritus_pool. Can be provided to the limits
argument of the plot.mdl_rn function.
Examples
if (FALSE) {
get_limits(result = list(result_rand, result_attr))
}