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Load survey block data (polygon, point, or coordinate table)

Source: R/utils.R
load_survey_blocks.Rd

Returns built-in grid datasets as either polygons, centroids, or coordinates. Available datasets include the Synoptic and HBLL survey grids (2x2 km square grids), MSSM grid, and SYN SOG grid. Note that centroid and coordinate outputs may fall on land rather than in the ocean. While suitable for visualization and basic modeling, these points should not be used directly for extracting oceanographic covariates - instead use polygon and extract as appropriate.

Usage

load_survey_blocks(
  dataset = "syn_hbll",
  type = c("polygon", "centroid", "XY"),
  active_only = TRUE
)

Arguments

dataset

Character string specifying the dataset to load. One of:

  • "syn_hbll" (default): Synoptic and HBLL survey grids (2x2 km square grids that may overlap with land).

  • "mssm": MSSM survey grid data, see gfdata::mssm_grid.

  • "syn_sog": Strait of Georgia Synoptic Bottom Trawl grid (only active blocks available).

type

Character string specifying the output format. One of:

  • "polygon" (default): returns an sf object with polygon geometries.

  • "centroid": returns an sf object with the centroid point for each block.

  • "XY": returns a tibble with columns X and Y (in kilometres), representing point-on-surface coordinates extracted from each polygon.

active_only

Logical. If TRUE (default), only returns active survey blocks.

Value

Either an sf object or a tbl depending on type.

Examples

if (FALSE) { # \dontrun{
# Load synoptic and HBLL survey grids as polygons (default)
load_survey_blocks() |>
  ggplot() +
  geom_sf(aes(fill = survey_abbrev)) +
  theme_minimal()

# Load MSSM grid as centroids
load_survey_blocks(dataset = "mssm", type = "centroid") |>
  ggplot() +
  geom_sf(aes(colour = survey_abbrev)) +
  theme_minimal()

# Load SOG grid as coordinates
load_survey_blocks(dataset = "syn_sog", type = "XY") |>
  ggplot() +
  geom_point(aes(x = X, y = Y)) +
  theme_minimal()
} # }