Demos for v4

assets/demo/akgfmaps_SCRUG_20250122/geopackages.R

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+# Example: Access data directly from a geopackage
+# SCRUG, akgfmaps, January 22, 2025
+# Created by Sean Rohan <[email protected]>
+
+# Loading layers directly from built-in Geopackage
+# Geopackages are an open, standards-based, platform-independent format for storing geospatial data.
+# They are based on SQLite, can store multiple layers and data types in one file.
+
+library(akgfmaps)
+library(dplyr)
+
+# Filepath to geopackage with AFSC bottom trawl survey layers
+gpkg_fpath <- system.file("extdata", "afsc_bottom_trawl_surveys.gpkg", package = "akgfmaps")
+
+# Inpsect the layers at the dsn (data source name).
+# There are four layers in individual tables (called 'layers' in sf)
+sf::st_layers(dsn = gpkg_fpath)
+
+# Load all of of the features from the survey_area layer
+survey_areas <- sf::st_read(dsn = gpkg_fpath,
+                            layer = "survey_area")
+
+survey_areas
+
+# Plot the survey areas
+ggplot() +
+  geom_sf(data = survey_areas,
+          mapping = aes(color = SURVEY_NAME),
+          fill = NA) +
+  facet_wrap(~DESIGN_YEAR) +
+  theme(legend.position = "bottom")
+
+# Filter to retreive the NBS survey area
+nbs_area <- dplyr::filter(survey_areas, SURVEY_DEFINITION_ID == 143)
+
+ggplot() +
+  geom_sf(data = nbs_area,
+          mapping = aes(color = SURVEY_NAME)) +
+  facet_wrap(~DESIGN_YEAR) +
+  theme(legend.position = "bottom")
+
+# Alternatively, we can retrieve features from the geopackage using a SQLite query.
+# In this case, retrieve GOA stratum polygons for the 1984 and 2025 design years.
+goa_strata <- sf::st_read(dsn = gpkg_fpath,
+                          query =
+                          "SELECT
+                            AREA_TYPE,
+                            SURVEY_DEFINITION_ID,
+                            DESIGN_YEAR,
+                            AREA_ID AS STRATUM,
+                            AREA_M2,
+                            GEOM
+                            FROM SURVEY_STRATA
+                            WHERE SURVEY_DEFINITION_ID = 47"
+                          )
+
+head(goa_strata)
+table(goa_strata$DESIGN_YEAR)
+
+# Plotting the 1984 and 2025 GOA survey strata
+ggplot() +
+  geom_sf(data = goa_strata,
+          mapping = aes(fill = factor(STRATUM)),
+          color = NA) +
+  scale_fill_viridis_d(option = "H") +
+  facet_wrap(~DESIGN_YEAR, nrow = 2) +
+  theme(legend.position = "none",
+        axis.title = element_blank())
+
+
+# Land layers
+sf::st_layers(dsn = system.file("extdata", "land_layers.gpkg", package = "akgfmaps"))

assets/demo/akgfmaps_SCRUG_20250122/installing_akgfmaps.R

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+# Installing akgfmaps
+
+install.packages("devtools", "dplyr")
+devtools::install_github(repo = "afsc-gap-products/akgfmaps")