make_grid function

Make a depth stratified survey grid

This function sets up a depth stratified survey grid. A simple gradient in depth is simulated using stats::spline (default) with a shallow portion, shelf and deep portion. Adding covariance to the depth simulation is an option.

make_grid(
  x_range = c(-140, 140),
  y_range = c(-140, 140),
  res = c(3.5, 3.5),
  shelf_depth = 200,
  shelf_width = 100,
  depth_range = c(0, 1000),
  n_div = 1,
  strat_breaks = seq(0, 1000, by = 40),
  strat_splits = 2,
  method = "spline"
)

Arguments

• x_range: Range (min x, max x) in x dimension in km
• y_range: Range (min y, max y) in y dimension in km
• res: Resolution, in km, of the grid cells
• shelf_depth: Approximate depth of the shelf in m
• shelf_width: Approximate width of the shelf in km
• depth_range: Range (min depth, max depth) in depth in m
• n_div: Number of divisions to include
• strat_breaks: Define strata given these depth breaks
• strat_splits: Number of times to horizontally split strat (i.e. easy way to increase the number of strata)
• method: Use a "spline", "loess" or "bezier" to generate a smooth gradient or simply use "linear" interpolation?

Returns

Returns a stars object with 2 dimensions (x and y) and 4 attributes (depth, cell, division, strat).

Examples

r <- make_grid(res = c(10, 10))
plot(r)

p <- sf::st_as_sf(r["strat"], as_points = FALSE, merge = TRUE)
plot(p)

See Also

survey_grid