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Plot a map object

Source: R/plot.map.R
plot.map.Rd

This function plots a GeoPressureR map object.

You can plot on top of the map a path, this uses the plot_path() function.

Our maps are defined in lat-lon (i.e., EPSG:4326), but the display of maps on web map are nearly always in web mercator (i.e., EPSG:3857). We therefore need to reproject our map for display. However, we don't really want to interpolate the map as each pixel might be important to visualize. We therefore re-project with a near-neighbour interpolation (method = "near" in terra::project()). Yet to avoid having pixel misplaced, we generally need to use a projection with a finer resolution. The argument fac_res_proj controls the relative change of resolution between the original map to the projected map.

Usage

# S3 method for class 'map'
plot(
  x,
  path = NULL,
  thr_likelihood = 1,
  plot_leaflet = TRUE,
  provider = NULL,
  provider_options = leaflet::providerTileOptions(),
  palette = NULL,
  opacity = 0.8,
  legend = FALSE,
  fac_res_proj = 4,
  ...
)

Arguments

x

a GeoPressureR map object

path

a GeoPressureR path data.frame

thr_likelihood

Threshold to display likelihood values.

plot_leaflet

logical to use an interactive leaflet map instead of terra::plot

provider

optional tile provider name (see leaflet::providers). When NULL, uses all available GeoPressureR basemap layers; see the Basemap API keys section.

provider_options

tile options. See leaflet::addProviderTiles() and leaflet::providerTileOptions().

palette

color palette name or vector of colors.

opacity

opacity of the raster layer in leaflet.

legend

logical to display the legend.

fac_res_proj

Factor of the resolution of the reprojection (see details above). A value of 1 will roughly reproject on a map with similar size resulting in relatively high inaccuracy of the pixel displayed. Increasing this factor will reduce the uncertainty but might also increase the computational cost of the reprojection.

...

additional parameters passed to leaflet::addRasterImage() or terra::plot().

Value

a plot or leaflet object.

Basemap API keys

Interactive maps always offer Esri basemaps (gray canvas, imagery and topographic). CARTO, Mapbox and MapTiler basemaps are added to the layer control only when their API key is stored in your system keyring. Get a key from each provider:

Then store each key once:

keyring::key_set_with_value("CARTO_API_KEY", password = "<your CARTO API key>")
keyring::key_set_with_value("MAPBOX_ACCESS_TOKEN", password = "<your Mapbox token>")
keyring::key_set_with_value("MAPTILER_API_KEY", password = "<your MapTiler API key>")

Mapbox access tokens are visible in the browser when a map is rendered. Use a public, read-only token rather than a secret token.

See also

plot_path() plot.tag()

Examples

withr::with_dir(system.file("extdata", package = "GeoPressureR"), {
  tag <- tag_create("18LX", quiet = TRUE) |>
    tag_label(quiet = TRUE) |>
    tag_set_map(
      extent = c(-16, 23, 0, 50),
      scale = 4
    ) |>
    geopressure_map(quiet = TRUE)
})

plot(tag$map_pressure)



plot(tag$map_pressure, plot_leaflet = FALSE)


# `thr_likelihood` can be used to visualize its effect in `graph_create`
plot(tag$map_pressure,
  thr_likelihood = 0.9,
  palette = "viridis",
  opacity = 1,
  provider = "Esri.WorldGrayCanvas"
)