Add hypsograph to Aeme object

Usage

add_hypsograph(
  aeme = NULL,
  hypsograph = NULL,
  surf_elev = 0,
  lake_depth = NULL,
  lake_area = NULL,
  ext_elev = 0
)

aeme: aeme; object.
hypsograph: data frame with columns "depth" and "area". Depth should be monotonic decreasing and area should be monotonic increasing. If elevation is not provided, it will be calculated as depth + lake elevation. If NULL, a simple hypsograph will be generated using lake depth and area.
surf_elev: Lake surface elevation (m). Required if hypsograph is NULL.
lake_depth: Lake maximum depth (m). Required if hypsograph is NULL.
lake_area: Lake surface area (m2). Required if hypsograph is NULL.
ext_elev: numeric; metres to extend the hypograph by.

Aeme object with hypsograph added

depth <- seq(-5, 0, by = 0.5)
area <- c(0, 10, 30, 50, 70, 90, 110, 130, 150, 170, 190)
hypsograph <- data.frame(depth = depth, area = area)