R/R6Map.R
In csaybar/rgee: R Bindings for Calling the 'Earth Engine' API
#' R6 class to display Earth Engine (EE) spatial objects
#'
#' @description Create interactive visualizations of spatial EE objects
#' (ee$Geometry, ee$Image, ee$Feature, and ee$FeatureCollection)
#' using \code{leaflet}.
#'
#' @details
#' `Map` use the Earth Engine method
#' \href{https://developers.google.com/earth-engine/api_docs#ee.data.getmapid/}{
#' getMapId} to fetch and return an ID dictionary being used to create
#' layers in a \code{leaflet} object. Users can specify visualization
#' parameters to Map$addLayer by using the visParams argument. Each Earth
#' Engine spatial object has a specific format. For
#' \code{ee$Image}, the
#' \href{https://developers.google.com/earth-engine/guides/image_visualization}{
#' parameters} available are:
#'
#' \tabular{lll}{
#' \strong{Parameter}\tab \strong{Description} \tab \strong{Type}\cr
#' \strong{bands} \tab Comma-delimited list of three band names to be
#' mapped to RGB \tab list \cr
#' \strong{min} \tab Value(s) to map to 0 \tab number or list of three
#' numbers, one for each band \cr
#' \strong{max} \tab Value(s) to map to 1 \tab number or list of three
#' numbers, one for each band \cr
#' \strong{gain} \tab Value(s) by which to multiply each pixel value \tab
#' number or list of three numbers, one for each band \cr
#' \strong{bias} \tab Value(s) to add to each Digital Number (DN)
#' value \tab number or list of three numbers, one for each band \cr
#' \strong{gamma} \tab Gamma correction factor(s) \tab number or list of
#' three numbers, one for each band \cr
#' \strong{palette} \tab List of CSS-style color strings
#' (single-band images only) \tab comma-separated list of hex strings \cr
#' \strong{opacity} \tab The opacity of the layer (0.0 is fully transparent
#' and 1.0 is fully opaque) \tab number \cr
#' }
#'
#' If you add an \code{ee$Image} to Map$addLayer without any additional
#' parameters, by default it assigns the first three bands to red,
#' green, and blue bands, respectively. The default stretch is based on the
#' min-max range. On the other hand, the available parameters for
#' \code{ee$Geometry}, \code{ee$Feature}, and \code{ee$FeatureCollection}
#' are:
#'
#' \itemize{
#' \item \strong{color}: A hex string in the format RRGGBB specifying the
#' color to use for drawing the features. By default #000000.
#' \item \strong{pointRadius}: The radius of the point markers. By default 3.
#' \item \strong{strokeWidth}: The width of lines and polygon borders. By
#' default 3.
#' }
#'
#' @returns Object of class \code{leaflet} and \code{EarthEngineMap}, with the
#' following extra parameters: tokens, name, opacity, shown, min, max, palette,
#' position, and legend. Use the $ method to retrieve the data (e.g. m$rgee$min).
#'
#' @export
R6Map <- R6::R6Class(
classname = "EarthEngineMap",
public = list(
#' @field lon The longitude of the center, in degrees.
lon = NULL,
#' @field lat The latitude of the center, in degrees.
lat = NULL,
#' @field zoom The zoom level, from 1 to 24.
zoom = NULL,
#' @field save_maps Should `R6Map` save the previous maps?. If TRUE, Map
#' will work in a OOP style, otherwise will be functional programming style.
save_maps = NULL,
#' @field previous_map_left Container of maps in the left side.
previous_map_left = NULL,
#' @field previous_map_right Container of maps in the right side.
previous_map_right = NULL,
#' @description Constructor of R6Map.
#' @param lon The longitude of the center, in degrees. By default -76.942478.
#' @param lat The latitude of the center, in degrees. By default -12.172116.
#' @param zoom The zoom level, from 1 to 24. By default 18.
#' @param save_maps Should `R6Map` save previous maps?.
#' @return A new `EarthEngineMap` object.
initialize = function(lon = -76.942478, lat = -12.172116 , zoom = 18, save_maps = TRUE) {
self$lon <- lon
self$lat <- lat
self$zoom <- zoom
self$save_maps <- save_maps
self$previous_map_left = private$ee_mapview()
self$previous_map_right = private$ee_mapview()
},
#' @description Reset to initial arguments.
#' @param lon The longitude of the center, in degrees. By default -76.942478.
#' @param lat The latitude of the center, in degrees. By default -12.172116.
#' @param zoom The zoom level, from 1 to 24. By default 18.
#' @param save_maps Should `R6Map` save previous maps?.
#' @return A new `EarthEngineMap` object.
#' @examples
#' library(rgee)
#' ee_Initialize()
#'
#' # Load an Image
#' image <- ee$Image("LANDSAT/LC08/C01/T1/LC08_044034_20140318")
#'
#' # Create
#' Map <- R6Map$new()
#' Map$centerObject(image)
#'
#' # Simple display: Map just will
#' Map$addLayer(image, list(min=0, max = 10000, bands = c("B4", "B3", "B2")), name = "l8_01")
#' Map # display map
#'
#' Map$reset() # Reset arguments
#' Map
reset = function(lon = -76.942478, lat = -12.172116 , zoom = 18, save_maps = TRUE) {
self$lon <- lon
self$lat <- lat
self$zoom <- zoom
self$save_maps <- save_maps
self$previous_map_left = private$ee_mapview()
self$previous_map_right = private$ee_mapview()
},
#' @description
#' Display a \code{EarthEngineMap} object.
#' @return An `EarthEngineMap` object.
print = function() {
m1 <- private$get_previous_map_right()
m2 <- private$get_previous_map_left()
if (is.null(m1$rgee$position) & is.null(m2$rgee$position)) {
m3 <- m1
} else {
m3 <- m2 | m1
}
print(m3)
},
#' @description
#' Centers the map view at the given coordinates with the given zoom level. If
#' no zoom level is provided, it uses 10 by default.
#' @param lon The longitude of the center, in degrees. By default -76.942478.
#' @param lat The latitude of the center, in degrees. By default -12.172116.
#' @param zoom The zoom level, from 1 to 24. By default 18.
#' @return No return value, called to set initial coordinates and zoom.
#' @examples
#' library(rgee)
#'
#' ee_Initialize()
#'
#' Map <- R6Map$new()
#' Map$setCenter(lon = -76, lat = 0, zoom = 5)
#' Map
#'
#' # Map$lat
#' # Map$lon
#' # Map$zoom
setCenter = function(lon = 0, lat = 0, zoom = 10) {
private$upgrade_center_right(lon, lat, zoom)
private$upgrade_center_left(lon, lat, zoom)
private$set_lat(lat)
private$set_lon(lon)
private$set_zoom(zoom)
},
#' @description
#' Sets the zoom level of the map.
#' @param zoom The zoom level, from 1 to 24. By default 10.
#' @return No return value, called to set zoom.
#' @examples
#' library(rgee)
#'
#' ee_Initialize()
#'
#' Map <- R6Map$new()
#' Map$setZoom(zoom = 4)
#' Map
#'
#' # Map$lat
#' # Map$lon
#' # Map$zoom
setZoom = function(zoom = 10) {
private$upgrade_center_right(self$lon, self$lat, zoom)
private$upgrade_center_left(self$lon, self$lat, zoom)
private$set_zoom(zoom)
},
#' @description
#' Centers the map view on a given object. If no zoom level is provided, it
#' will be predicted according to the bounds of the Earth Engine object
#' specified.
#' @param eeObject Earth Engine spatial object.
#' @param zoom The zoom level, from 1 to 24. By default NULL.
#' @param maxError Max error when input image must be reprojected to an
#' explicitly requested result projection or geodesic state.
#' @return No return value, called to set zoom.
#' @examples
#' library(rgee)
#'
#' ee_Initialize()
#'
#' Map <- R6Map$new()
#' image <- ee$Image("LANDSAT/LC08/C01/T1/LC08_044034_20140318")
#' Map$centerObject(image)
#' Map
centerObject = function(eeObject,
zoom = NULL,
maxError = ee$ErrorMargin(1)) {
viewer_params <- private$get_center(eeObject, zoom, maxError)
self$setCenter(viewer_params$lon, viewer_params$lat, viewer_params$zoom)
},
#' @description
#'
#' Adds a given Eath Engine spatial object to the map as a layer
#'
#' @param eeObject The Earth Engine spatial object to display in the interactive map.
#' @param visParams List of parameters for visualization. See details.
#' @param name The name of layers.
#' @param shown A flag indicating whether layers should be on by default.
#' @param opacity The layer's opacity represented as a number between 0 and 1. Defaults to 1.
#' @param legend Should a legend be plotted?. Only the legend of the first image is displayed.
#' @param position Character. Activate panel creation. If "left" the map will be displayed in
#' the left panel. Otherwise, if it is "right" the map will be displayed in the right panel.
#' By default NULL (No panel will be created).
#'
#' @return An `EarthEngineMap` object.
#'
#' @examples
#'
#' library(rgee)
#' ee_Initialize()
#'
#' # Load an Image
#' image <- ee$Image("LANDSAT/LC08/C01/T1/LC08_044034_20140318")
#'
#' # Create
#' Map <- R6Map$new()
#' Map$centerObject(image)
#'
#' # Simple display: Map just will
#' Map$addLayer(image, list(min=0, max = 10000, bands = c("B4", "B3", "B2")), name = "l8_01")
#' Map$addLayer(image, list(min=0, max = 20000, bands = c("B4", "B3", "B2")), name = "l8_02")
#'
#' # Simple display: Map just will (if the position is not specified it will
#' # be saved on the right side)
#' Map$reset() # Reset Map to the initial arguments.
#' Map$centerObject(image)
#' Map$addLayer(image, list(min=0, max=10000, bands = c("B4", "B3", "B2")), name = "l8_left", position = "left")
#' Map$addLayer(image, list(min=0, max=20000, bands = c("B4", "B3", "B2")), name = "l8_right")
#'
addLayer = function(eeObject,
visParams = NULL,
name = NULL,
shown = TRUE,
opacity = 1,
position = NULL,
legend = FALSE) {
# check packages
ee_check_packages("Map$addLayer", c("jsonlite", "leaflet", "leafem"))
if (is.null(visParams)) {
visParams <- list()
}
# Earth Engine Spatial object
ee_spatial_object <- ee_get_spatial_objects("Simple")
if (!any(class(eeObject) %in% ee_spatial_object)) {
stop(
"The eeObject argument must be an instance of one",
" of ee$Image, ee$Geometry, ee$Feature, or ee$FeatureCollection."
)
}
if (any(class(eeObject) %in% ee_get_spatial_objects("Table"))) {
features <- ee$FeatureCollection(eeObject)
# If vizparams is NULL
width <- 2
if (!is.null(visParams[["width"]])) {
width <- visParams[["width"]]
}
color <- "000000"
if (!is.null(visParams[["color"]])) {
color <- visParams[["color"]]
}
# Convert features to a images
image_fill <- features %>%
ee$FeatureCollection$style(fillColor = color) %>%
ee$Image$updateMask(ee$Image$constant(0.5))
image_outline <- features %>%
ee$FeatureCollection$style(
color = color,
fillColor = "00000000",
width = width
)
image <- ee$Image$blend(image_fill, image_outline)
} else {
ee_img_viz <- function(...) ee$Image$visualize(eeObject, ...)
image <- do.call(ee_img_viz, visParams)
}
# If name is null try to obtain from image metadata if not untitled_
# would be the name.
if (is.null(name)) {
name <- tryCatch(
expr = ee_get_system_id(eeObject),
error = function(e) basename(tempfile(pattern = "untitled_"))
)
if (is.null(name)) name <- basename(tempfile(pattern = "untitled_"))
}
# Get token
tile <- get_ee_image_url(image)
# Using the previous token create a map using leaflet package
map <- private$ee_addTile(
tile = tile,
name = name,
visParams = visParams,
shown = shown,
opacity = opacity,
position = position
)
if (legend) {
map <- ee_add_legend(map, eeObject, visParams, name)
}
if (isTRUE(self$save_maps)) {
# Save the previous map in previous_map_left or previous_map_right
# according to posisa tion argument.
private$save_map(map, position = position)
} else {
map
}
},
#' @description
#'
#' Adds a given ee$ImageCollection to the map as multiple layers.
#'
#' @param eeObject ee$ImageCollection to display in the interactive map.
#' @param visParams List of parameters for visualization. See details.
#' @param nmax Numeric. The maximum number of images to display. By default 5.
#' @param name The name of layers.
#' @param shown A flag indicating whether layers should be on by default.
#' @param opacity The layer's opacity represented as a number between 0 and 1. Defaults to 1.
#' @param legend Should a legend be plotted?. Only the legend of the first image is displayed.
#' @param position Character. Activate panel creation. If "left" the map will be displayed in
#' the left panel. Otherwise, if it is "right" the map will be displayed in the right panel.
#' By default NULL (No panel will be created).
#'
#' @return A `EarthEngineMap` object.
#' @examples
#' library(sf)
#' library(rgee)
#'
#' ee_Initialize()
#'
#' Map <- R6Map$new()
#'
#' nc <- st_read(system.file("shape/nc.shp", package = "sf")) %>%
#' st_transform(4326) %>%
#' sf_as_ee()
#'
#' ee_s2 <- ee$ImageCollection("COPERNICUS/S2")$
#' filterDate("2016-01-01", "2016-01-31")$
#' filterBounds(nc) %>%
#' ee_get(0:2)
#'
#' Map$centerObject(nc$geometry())
#' Map$addLayers(eeObject = ee_s2, legend = TRUE, position = "right")
#' Map$reset()
#'
#' # digging up the metadata
#' Map$previous_map_right$rgee$tokens
addLayers = function(eeObject,
visParams = NULL,
nmax = 5,
name = NULL,
shown = TRUE,
position = NULL,
opacity = 1,
legend = FALSE) {
# check packages
ee_check_packages("Map$addLayers", c("jsonlite", "leaflet"))
# is an ee.imagecollection.ImageCollection?
if (!any(class(eeObject) %in% "ee.imagecollection.ImageCollection")) {
stop("eeObject argument is not an ee$imagecollection$ImageCollection")
}
if (is.null(visParams)) {
visParams <- list()
}
# size of objects
eeObject_size <- eeObject %>%
ee$ImageCollection$size() %>%
ee$Number$getInfo()
m_img_list <- list()
if (is.null(name)) {
name <- tryCatch(
expr = eeObject %>%
ee$ImageCollection$aggregate_array("system:id") %>%
ee$List$getInfo() %>%
ee_utils_py_to_r() %>%
basename(),
error = function(e) sprintf("untitled_%02d", seq_len(eeObject_size))
)
if (length(name) == 0 | is.null(name)) name <- sprintf("untitled_%02d", seq_len(eeObject_size))
}
if (length(name) == 1) {
name <- sprintf("%s_%02d", name, seq_len(eeObject_size))
}
if (length(name) == length(eeObject_size)) {
stop("name does not have the same length than eeObject$size()$getInfo().")
}
m_img_list <- list()
for (index in seq_len(eeObject_size)) {
py_index <- index - 1
if (index == 1) {
m_img <- self$addLayer(
eeObject = ee_get(eeObject, index = py_index)$first(),
visParams = visParams,
name = name[index],
shown = shown,
opacity = opacity,
position = position,
legend = legend
)
} else {
m_img <- self$addLayer(
eeObject = ee_get(eeObject, index = py_index)$first(),
visParams = visParams,
name = name[index],
shown = shown,
opacity = opacity,
position = position,
legend = FALSE
)
}
m_img_list[[index]] <- m_img
}
if (isFALSE(self$save_maps)) {
Reduce('+', m_img_list)
}
}
),
private = list(
get_previous_map_right = function() {
self$previous_map_right
},
set_previous_map_right = function(val) {
self$previous_map_right <- val
},
get_previous_map_left = function() {
self$previous_map_left
},
set_previous_map_left = function(val) {
self$previous_map_left <- val
},
set_lat = function(val) {
self$lat <- val
},
set_lon = function(val) {
self$lon <- val
},
set_zoom = function(val) {
self$zoom <- val
},
get_center = function(eeObject, zoom, maxError) {
if (any(class(eeObject) %in% "ee.featurecollection.FeatureCollection")) {
message("NOTE: Center obtained from the first element.")
eeObject <- ee$Feature(ee$FeatureCollection$first(eeObject))
}
if (any(class(eeObject) %in% ee_get_spatial_objects("Nongeom"))) {
center <- tryCatch(
expr = eeObject$
geometry()$
centroid(maxError)$
getInfo() %>%
'[['('coordinates') %>%
ee_utils_py_to_r(),
error = function(e) {
message(
"The centroid coordinate was not possible",
" to estimate, assigning: c(0,0)"
)
c(0, 0)
}
)
if (is.null(center)) {
message(
"The centroid coordinate was not possible",
" to estimate, assigning: c(0,0)"
)
center <- c(0, 0)
}
} else if (any(class(eeObject) %in% "ee.geometry.Geometry")) {
center <- tryCatch(
expr = eeObject$
centroid(maxError)$
coordinates()$
getInfo() %>%
ee_utils_py_to_r(),
error = function(e) {
message(
"The centroid coordinate was not possible",
" to estimate, assigning: c(0,0)"
)
c(0, 0)
}
)
} else {
stop("Spatial Earth Engine Object not supported")
}
if (is.null(zoom)) {
zoom <- ee_getZoom(eeObject, maxError = maxError)
}
# Set new initial view
list(lon = center[1], lat = center[2], zoom = zoom)
},
ee_mapview = function() {
# check packages
private$ee_check_packages("ee_mapview", "leaflet")
m <- private$leaflet_default()
m$x$setView[[1]] <- c(self$lat, self$lon)
m$x$setView[[2]] <- if (is.null(self$zoom)) 1 else self$zoom
# EarthEngine Map parameters
# m$rgee$tokens <- NA
# m$rgee$name <- NA
# m$rgee$opacity <- NA
# m$rgee$shown <- NA
# m$rgee$position <- NA
# # legend parameters
# m$rgee$min <- NA
# m$rgee$max <- NA
# m$rgee$palette <- list(NA)
# m$rgee$legend <- NA
m
},
ee_addTile = function(tile, name, visParams, shown, opacity, position) {
# check packages
ee_check_packages("Map$addLayer", c("leaflet"))
m <- private$ee_mapview() %>%
leaflet::addTiles(
urlTemplate = tile,
layerId = name,
group = name,
options = leaflet::tileOptions(opacity = opacity)
) %>%
ee_mapViewLayersControl(names = name) %>%
leaflet::hideGroup(if (!shown) name else NULL)
# map parameters
m$rgee$tokens <- tile
m$rgee$name <- name
m$rgee$opacity <- opacity
m$rgee$shown <- shown
m$rgee$position <- position
# legend parameters
m$rgee$min <- if (is.null(visParams$min)) NA else visParams$min
m$rgee$max <- if (is.null(visParams$max)) NA else visParams$max
m$rgee$palette <- if (is.null(visParams$palette)) list(NA) else list(visParams$palette)
m$rgee$legend <- FALSE
m
},
save_map = function(map, position = NULL) {
if (is.null(position)) {
private$set_previous_map_right(self$previous_map_right + map)
} else {
if (tolower(position) == "right") {
private$set_previous_map_right(self$previous_map_right + map)
} else if (tolower(position) == "left") {
private$set_previous_map_left(self$previous_map_left + map)
} else {
stop("position should be a character either 'right' or 'left'")
}
}
},
leaflet_default = function(lon = -76.942478, lat = -12.172116, zoom = 18, default_maps = NULL) {
if (is.null(default_maps)) {
default_maps <- c(
"CartoDB.Positron", "OpenStreetMap",
"CartoDB.DarkMatter", "Esri.WorldImagery",
"OpenTopoMap"
)
}
m <- private$initBaseMaps(default_maps)
m <- leaflet::setView(map = m, lon, lat, zoom)
m <- leaflet::addLayersControl(
map = m,
baseGroups = default_maps,
position = "topleft"
)
m <- leaflet::addScaleBar(map = m, position = "bottomleft")
m <- leafem::addMouseCoordinates(m)
m <- leafem::addCopyExtent(m)
class(m) <- append(class(m),"EarthEngineMap")
m
},
initBaseMaps = function (map.types, canvas = FALSE, viewer.suppress = FALSE) {
lid <- seq_along(map.types)
m <- leaflet::leaflet(
height = NULL,
width = NULL,
options = leaflet::leafletOptions(
minZoom = 1, maxZoom = 52,
bounceAtZoomLimits = FALSE,
maxBounds = list(list(c(-90,-370)), list(c(90, 370))),
preferCanvas = canvas),
sizingPolicy = leaflet::leafletSizingPolicy(
viewer.suppress = viewer.suppress,
browser.external = viewer.suppress))
# add Tiles
m <- leaflet::addProviderTiles(
map = m,
provider = map.types[1],
layerId = map.types[1],
group = map.types[1],
options = leaflet::providerTileOptions(pane = "tilePane")
)
for (i in 2:length(map.types)) {
m <- leaflet::addProviderTiles(
map = m,
provider = map.types[i],
layerId = map.types[i],
group = map.types[i],
options = leaflet::providerTileOptions(pane = "tilePane"))
}
return(m)
},
upgrade_center_right = function(lon = 0, lat = 0, zoom = 10) {
self$previous_map_right <- self$previous_map_right %>%
leaflet::setView(lon, lat, zoom = zoom)
},
upgrade_center_left = function(lon = 0, lat = 0, zoom = 10) {
self$previous_map_left <- self$previous_map_left %>%
leaflet::setView(lon, lat, zoom = zoom)
},
ee_check_packages = function(fn_name, packages) {
pkg_exists <- rep(NA, length(packages))
counter <- 0
for(package in packages) {
counter <- counter + 1
pkg_exists[counter] <- requireNamespace(package, quietly = TRUE)
}
if (!all(pkg_exists)) {
to_install <- packages[!pkg_exists]
to_install_len <- length(to_install)
error_msg <- sprintf(
"%s required the %s: %s. Please install %s first.",
bold(fn_name),
if (to_install_len == 1) "package" else "packages",
paste0(bold(to_install), collapse = ", "),
if (to_install_len == 1) "it" else "them"
)
stop(error_msg)
}
}
)
)
#' R6 object (Map) to display Earth Engine (EE) spatial objects
#'
#' Create interactive visualizations of spatial EE objects
#' (ee$FeatureCollection, ee$ImageCollection, ee$Geometry, ee$Feature, and
#' ee$Image.) using \code{leaflet} in the backend.
#' @format An object of class environment with the
#' following functions:
#' \itemize{
#' \item \strong{addLayer(eeObject, visParams, name = NULL, shown = TRUE,
#' opacity = 1, legend = FALSE)}: Adds a given EE object to the map as a layer. \cr
#' \itemize{
#' \item \strong{eeObject:} The object to add to the interactive map.\cr
#' \item \strong{visParams:} List of parameters for visualization.
#' See details.\cr
#' \item \strong{name:} The name of the layer.\cr
#' \item \strong{shown:} A flag indicating whether the
#' layer should be on by default. \cr
#' \item \strong{opacity:} The layer's opacity represented as a number
#' between 0 and 1. Defaults to 1. \cr
#' \item \strong{legend:} Should a legend be plotted?. Ignore if \code{eeObject}
#' is not a single-band ee$Image.
#' }
#' \item \strong{addLayers(eeObject, visParams, name = NULL, shown = TRUE,
#' opacity = 1, legend = FALSE)}: Adds a given ee$ImageCollection to the map
#' as multiple layers. \cr
#' \itemize{
#' \item \strong{eeObject:} The ee$ImageCollection to add to the interactive map.\cr
#' \item \strong{visParams:} List of parameters for visualization.
#' See details.\cr
#' \item \strong{name:} The name of layers.\cr
#' \item \strong{shown:} A flag indicating whether
#' layers should be on by default. \cr
#' \item \strong{opacity:} The layer's opacity represented as a number
#' between 0 and 1. Defaults to 1. \cr
#' \item \strong{nmax:} Numeric. The maximum number of images to display.
#' By default 5. \cr
#' \item \strong{legend:} Should a legend be plotted?. Only the legend of
#' the first image is displayed.
#' }
#' \item \strong{setCenter(lon = 0, lat = 0, zoom = NULL)}: Centers the map
#' view at the given coordinates with the given zoom level. If no zoom level
#' is provided, it uses 1 by default.
#' \itemize{
#' \item \strong{lon:} The longitude of the center, in degrees.\cr
#' \item \strong{lat:} The latitude of the center, in degrees.\cr
#' \item \strong{zoom:} The zoom level, from 1 to 24.
#' }
#' \item \strong{setZoom(zoom = NULL)}: Sets the zoom level of the map.
#' \itemize{
#' \item \strong{zoom:} The zoom level, from 1 to 24.
#' }
#' \item \strong{centerObject(eeObject, zoom = NULL,
#' maxError = ee$ErrorMargin(1))}: Centers the
#' map view on a given object. If no zoom level is provided, it will
#' be predicted according to the bounds of the Earth Engine object specified.
#' \itemize{
#' \item \strong{eeObject:} EE object.\cr
#' \item \strong{zoom:} The zoom level, from 1 to 24.
#' \item \strong{maxError:} Max error when input
#' image must be reprojected to an explicitly
#' requested result projection or geodesic state.
#' }
#' }
#'
#' @details
#' `Map` use the Earth Engine method
#' \href{https://developers.google.com/earth-engine/api_docs#ee.data.getmapid/}{
#' getMapId} to fetch and return an ID dictionary being used to create
#' layers in a \code{leaflet} object. Users can specify visualization
#' parameters to Map$addLayer by using the visParams argument. Each Earth
#' Engine spatial object has a specific format. For
#' \code{ee$Image}, the
#' \href{https://developers.google.com/earth-engine/guides/image_visualization}{
#' parameters} available are:
#'
#' \tabular{lll}{
#' \strong{Parameter}\tab \strong{Description} \tab \strong{Type}\cr
#' \strong{bands} \tab Comma-delimited list of three band names to be
#' mapped to RGB \tab list \cr
#' \strong{min} \tab Value(s) to map to 0 \tab number or list of three
#' numbers, one for each band \cr
#' \strong{max} \tab Value(s) to map to 1 \tab number or list of three
#' numbers, one for each band \cr
#' \strong{gain} \tab Value(s) by which to multiply each pixel value \tab
#' number or list of three numbers, one for each band \cr
#' \strong{bias} \tab Value(s) to add to each Digital Number (DN)
#' value \tab number or list of three numbers, one for each band \cr
#' \strong{gamma} \tab Gamma correction factor(s) \tab number or list of
#' three numbers, one for each band \cr
#' \strong{palette} \tab List of CSS-style color strings
#' (single-band images only) \tab comma-separated list of hex strings \cr
#' \strong{opacity} \tab The opacity of the layer (0.0 is fully transparent
#' and 1.0 is fully opaque) \tab number \cr
#' }
#'
#' If you add an \code{ee$Image} to Map$addLayer without any additional
#' parameters, by default it assigns the first three bands to red,
#' green, and blue bands, respectively. The default stretch is based on the
#' min-max range. On the other hand, the available parameters for
#' \code{ee$Geometry}, \code{ee$Feature}, and \code{ee$FeatureCollection}
#' are:
#'
#' \itemize{
#' \item \strong{color}: A hex string in the format RRGGBB specifying the
#' color to use for drawing the features. By default #000000.
#' \item \strong{pointRadius}: The radius of the point markers. By default 3.
#' \item \strong{strokeWidth}: The width of lines and polygon borders. By
#' default 3.
#' }
#' @returns Object of class leaflet, with the following extra parameters: tokens, name,
#' opacity, shown, min, max, palette, and legend. Use the $ method to retrieve
#' the data (e.g. m$rgee$min).
#'
#' @examples
#' library(rgee)
#' library(sf)
#' ee_Initialize()
#'
#' # Case 1: Geometry*
#' geom1 <- ee$Geometry$Point(list(-73.53, -15.75))
#' Map$centerObject(geom1, zoom = 8)
#' m1 <- Map$addLayer(
#' eeObject = geom1,
#' visParams = list(
#' pointRadius = 10,
#' color = "FF0000"
#' ),
#' name = "Geometry-Arequipa"
#' )
#'
#' # Case 2: Feature
#' feature_arq <- ee$Feature(ee$Geometry$Point(list(-72.53, -15.75)))
#' m2 <- Map$addLayer(
#' eeObject = feature_arq,
#' name = "Feature-Arequipa"
#' )
#' m2 + m1
#'
#' # Case 4: Image
#' image <- ee$Image("LANDSAT/LC08/C01/T1/LC08_044034_20140318")
#' Map$centerObject(image)
#' m4 <- Map$addLayer(
#' eeObject = image,
#' visParams = list(
#' bands = c("B4", "B3", "B2"),
#' max = 10000
#' ),
#' name = "SF"
#' )
#'
#' # Case 5: ImageCollection
#' nc <- st_read(system.file("shape/nc.shp", package = "sf")) %>%
#' st_transform(4326) %>%
#' sf_as_ee()
#'
#' ee_s2 <- ee$ImageCollection("COPERNICUS/S2")$
#' filterDate("2016-01-01", "2016-01-31")$
#' filterBounds(nc) %>%
#' ee_get(0:4)
#' Map$centerObject(nc$geometry())
#' m5 <- Map$addLayers(ee_s2, legend = TRUE)
#' m5
#'
#' # Case 6: Map comparison
#' image <- ee$Image("LANDSAT/LC08/C01/T1/LC08_044034_20140318")
#' Map$centerObject(image)
#' m_ndvi <- Map$addLayer(
#' eeObject = image$normalizedDifference(list("B5", "B4")),
#' visParams = list(max = 0.7),
#' name = "SF_NDVI",
#' legend = TRUE
#' )
#' m6 <- m4 | m_ndvi
#' m6
#'
#' # Case 7: digging up the metadata
#' m6$rgee$tokens
#' m5$rgee$tokens
#' @export
Map <- R6Map$new(save_maps = FALSE)
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#' R6 class to display Earth Engine (EE) spatial objects
#'
#' @description Create interactive visualizations of spatial EE objects
#' (ee$Geometry, ee$Image, ee$Feature, and ee$FeatureCollection)
#' using \code{leaflet}.
#'
#' @details
#' `Map` use the Earth Engine method
#' \href{https://developers.google.com/earth-engine/api_docs#ee.data.getmapid/}{
#' getMapId} to fetch and return an ID dictionary being used to create
#' layers in a \code{leaflet} object. Users can specify visualization
#' parameters to Map$addLayer by using the visParams argument. Each Earth
#' Engine spatial object has a specific format. For
#' \code{ee$Image}, the
#' \href{https://developers.google.com/earth-engine/guides/image_visualization}{
#' parameters} available are:
#'
#' \tabular{lll}{
#' \strong{Parameter}\tab \strong{Description} \tab \strong{Type}\cr
#' \strong{bands} \tab Comma-delimited list of three band names to be
#' mapped to RGB \tab list \cr
#' \strong{min} \tab Value(s) to map to 0 \tab number or list of three
#' numbers, one for each band \cr
#' \strong{max} \tab Value(s) to map to 1 \tab number or list of three
#' numbers, one for each band \cr
#' \strong{gain} \tab Value(s) by which to multiply each pixel value \tab
#' number or list of three numbers, one for each band \cr
#' \strong{bias} \tab Value(s) to add to each Digital Number (DN)
#' value \tab number or list of three numbers, one for each band \cr
#' \strong{gamma} \tab Gamma correction factor(s) \tab number or list of
#' three numbers, one for each band \cr
#' \strong{palette} \tab List of CSS-style color strings
#' (single-band images only) \tab comma-separated list of hex strings \cr
#' \strong{opacity} \tab The opacity of the layer (0.0 is fully transparent
#' and 1.0 is fully opaque) \tab number \cr
#' }
#'
#' If you add an \code{ee$Image} to Map$addLayer without any additional
#' parameters, by default it assigns the first three bands to red,
#' green, and blue bands, respectively. The default stretch is based on the
#' min-max range. On the other hand, the available parameters for
#' \code{ee$Geometry}, \code{ee$Feature}, and \code{ee$FeatureCollection}
#' are:
#'
#' \itemize{
#' \item \strong{color}: A hex string in the format RRGGBB specifying the
#' color to use for drawing the features. By default #000000.
#' \item \strong{pointRadius}: The radius of the point markers. By default 3.
#' \item \strong{strokeWidth}: The width of lines and polygon borders. By
#' default 3.
#' }
#'
#' @returns Object of class \code{leaflet} and \code{EarthEngineMap}, with the
#' following extra parameters: tokens, name, opacity, shown, min, max, palette,
#' position, and legend. Use the $ method to retrieve the data (e.g. m$rgee$min).
#'
#' @export
R6Map <- R6::R6Class(
classname = "EarthEngineMap",
public = list(
#' @field lon The longitude of the center, in degrees.
lon = NULL,
#' @field lat The latitude of the center, in degrees.
lat = NULL,
#' @field zoom The zoom level, from 1 to 24.
zoom = NULL,
#' @field save_maps Should `R6Map` save the previous maps?. If TRUE, Map
#' will work in a OOP style, otherwise will be functional programming style.
save_maps = NULL,
#' @field previous_map_left Container of maps in the left side.
previous_map_left = NULL,
#' @field previous_map_right Container of maps in the right side.
previous_map_right = NULL,
#' @description Constructor of R6Map.
#' @param lon The longitude of the center, in degrees. By default -76.942478.
#' @param lat The latitude of the center, in degrees. By default -12.172116.
#' @param zoom The zoom level, from 1 to 24. By default 18.
#' @param save_maps Should `R6Map` save previous maps?.
#' @return A new `EarthEngineMap` object.
initialize = function(lon = -76.942478, lat = -12.172116 , zoom = 18, save_maps = TRUE) {
self$lon <- lon
self$lat <- lat
self$zoom <- zoom
self$save_maps <- save_maps
self$previous_map_left = private$ee_mapview()
self$previous_map_right = private$ee_mapview()
},
#' @description Reset to initial arguments.
#' @param lon The longitude of the center, in degrees. By default -76.942478.
#' @param lat The latitude of the center, in degrees. By default -12.172116.
#' @param zoom The zoom level, from 1 to 24. By default 18.
#' @param save_maps Should `R6Map` save previous maps?.
#' @return A new `EarthEngineMap` object.
#' @examples
#' library(rgee)
#' ee_Initialize()
#'
#' # Load an Image
#' image <- ee$Image("LANDSAT/LC08/C01/T1/LC08_044034_20140318")
#'
#' # Create
#' Map <- R6Map$new()
#' Map$centerObject(image)
#'
#' # Simple display: Map just will
#' Map$addLayer(image, list(min=0, max = 10000, bands = c("B4", "B3", "B2")), name = "l8_01")
#' Map # display map
#'
#' Map$reset() # Reset arguments
#' Map
reset = function(lon = -76.942478, lat = -12.172116 , zoom = 18, save_maps = TRUE) {
self$lon <- lon
self$lat <- lat
self$zoom <- zoom
self$save_maps <- save_maps
self$previous_map_left = private$ee_mapview()
self$previous_map_right = private$ee_mapview()
},
#' @description
#' Display a \code{EarthEngineMap} object.
#' @return An `EarthEngineMap` object.
print = function() {
m1 <- private$get_previous_map_right()
m2 <- private$get_previous_map_left()
if (is.null(m1$rgee$position) & is.null(m2$rgee$position)) {
m3 <- m1
} else {
m3 <- m2 | m1
}
print(m3)
},
#' @description
#' Centers the map view at the given coordinates with the given zoom level. If
#' no zoom level is provided, it uses 10 by default.
#' @param lon The longitude of the center, in degrees. By default -76.942478.
#' @param lat The latitude of the center, in degrees. By default -12.172116.
#' @param zoom The zoom level, from 1 to 24. By default 18.
#' @return No return value, called to set initial coordinates and zoom.
#' @examples
#' library(rgee)
#'
#' ee_Initialize()
#'
#' Map <- R6Map$new()
#' Map$setCenter(lon = -76, lat = 0, zoom = 5)
#' Map
#'
#' # Map$lat
#' # Map$lon
#' # Map$zoom
setCenter = function(lon = 0, lat = 0, zoom = 10) {
private$upgrade_center_right(lon, lat, zoom)
private$upgrade_center_left(lon, lat, zoom)
private$set_lat(lat)
private$set_lon(lon)
private$set_zoom(zoom)
},
#' @description
#' Sets the zoom level of the map.
#' @param zoom The zoom level, from 1 to 24. By default 10.
#' @return No return value, called to set zoom.
#' @examples
#' library(rgee)
#'
#' ee_Initialize()
#'
#' Map <- R6Map$new()
#' Map$setZoom(zoom = 4)
#' Map
#'
#' # Map$lat
#' # Map$lon
#' # Map$zoom
setZoom = function(zoom = 10) {
private$upgrade_center_right(self$lon, self$lat, zoom)
private$upgrade_center_left(self$lon, self$lat, zoom)
private$set_zoom(zoom)
},
#' @description
#' Centers the map view on a given object. If no zoom level is provided, it
#' will be predicted according to the bounds of the Earth Engine object
#' specified.
#' @param eeObject Earth Engine spatial object.
#' @param zoom The zoom level, from 1 to 24. By default NULL.
#' @param maxError Max error when input image must be reprojected to an
#' explicitly requested result projection or geodesic state.
#' @return No return value, called to set zoom.
#' @examples
#' library(rgee)
#'
#' ee_Initialize()
#'
#' Map <- R6Map$new()
#' image <- ee$Image("LANDSAT/LC08/C01/T1/LC08_044034_20140318")
#' Map$centerObject(image)
#' Map
centerObject = function(eeObject,
zoom = NULL,
maxError = ee$ErrorMargin(1)) {
viewer_params <- private$get_center(eeObject, zoom, maxError)
self$setCenter(viewer_params$lon, viewer_params$lat, viewer_params$zoom)
},
#' @description
#'
#' Adds a given Eath Engine spatial object to the map as a layer
#'
#' @param eeObject The Earth Engine spatial object to display in the interactive map.
#' @param visParams List of parameters for visualization. See details.
#' @param name The name of layers.
#' @param shown A flag indicating whether layers should be on by default.
#' @param opacity The layer's opacity represented as a number between 0 and 1. Defaults to 1.
#' @param legend Should a legend be plotted?. Only the legend of the first image is displayed.
#' @param position Character. Activate panel creation. If "left" the map will be displayed in
#' the left panel. Otherwise, if it is "right" the map will be displayed in the right panel.
#' By default NULL (No panel will be created).
#'
#' @return An `EarthEngineMap` object.
#'
#' @examples
#'
#' library(rgee)
#' ee_Initialize()
#'
#' # Load an Image
#' image <- ee$Image("LANDSAT/LC08/C01/T1/LC08_044034_20140318")
#'
#' # Create
#' Map <- R6Map$new()
#' Map$centerObject(image)
#'
#' # Simple display: Map just will
#' Map$addLayer(image, list(min=0, max = 10000, bands = c("B4", "B3", "B2")), name = "l8_01")
#' Map$addLayer(image, list(min=0, max = 20000, bands = c("B4", "B3", "B2")), name = "l8_02")
#'
#' # Simple display: Map just will (if the position is not specified it will
#' # be saved on the right side)
#' Map$reset() # Reset Map to the initial arguments.
#' Map$centerObject(image)
#' Map$addLayer(image, list(min=0, max=10000, bands = c("B4", "B3", "B2")), name = "l8_left", position = "left")
#' Map$addLayer(image, list(min=0, max=20000, bands = c("B4", "B3", "B2")), name = "l8_right")
#'
addLayer = function(eeObject,
visParams = NULL,
name = NULL,
shown = TRUE,
opacity = 1,
position = NULL,
legend = FALSE) {
# check packages
ee_check_packages("Map$addLayer", c("jsonlite", "leaflet", "leafem"))
if (is.null(visParams)) {
visParams <- list()
}
# Earth Engine Spatial object
ee_spatial_object <- ee_get_spatial_objects("Simple")
if (!any(class(eeObject) %in% ee_spatial_object)) {
stop(
"The eeObject argument must be an instance of one",
" of ee$Image, ee$Geometry, ee$Feature, or ee$FeatureCollection."
)
}
if (any(class(eeObject) %in% ee_get_spatial_objects("Table"))) {
features <- ee$FeatureCollection(eeObject)
# If vizparams is NULL
width <- 2
if (!is.null(visParams[["width"]])) {
width <- visParams[["width"]]
}
color <- "000000"
if (!is.null(visParams[["color"]])) {
color <- visParams[["color"]]
}
# Convert features to a images
image_fill <- features %>%
ee$FeatureCollection$style(fillColor = color) %>%
ee$Image$updateMask(ee$Image$constant(0.5))
image_outline <- features %>%
ee$FeatureCollection$style(
color = color,
fillColor = "00000000",
width = width
)
image <- ee$Image$blend(image_fill, image_outline)
} else {
ee_img_viz <- function(...) ee$Image$visualize(eeObject, ...)
image <- do.call(ee_img_viz, visParams)
}
# If name is null try to obtain from image metadata if not untitled_
# would be the name.
if (is.null(name)) {
name <- tryCatch(
expr = ee_get_system_id(eeObject),
error = function(e) basename(tempfile(pattern = "untitled_"))
)
if (is.null(name)) name <- basename(tempfile(pattern = "untitled_"))
}
# Get token
tile <- get_ee_image_url(image)
# Using the previous token create a map using leaflet package
map <- private$ee_addTile(
tile = tile,
name = name,
visParams = visParams,
shown = shown,
opacity = opacity,
position = position
)
if (legend) {
map <- ee_add_legend(map, eeObject, visParams, name)
}
if (isTRUE(self$save_maps)) {
# Save the previous map in previous_map_left or previous_map_right
# according to posisa tion argument.
private$save_map(map, position = position)
} else {
map
}
},
#' @description
#'
#' Adds a given ee$ImageCollection to the map as multiple layers.
#'
#' @param eeObject ee$ImageCollection to display in the interactive map.
#' @param visParams List of parameters for visualization. See details.
#' @param nmax Numeric. The maximum number of images to display. By default 5.
#' @param name The name of layers.
#' @param shown A flag indicating whether layers should be on by default.
#' @param opacity The layer's opacity represented as a number between 0 and 1. Defaults to 1.
#' @param legend Should a legend be plotted?. Only the legend of the first image is displayed.
#' @param position Character. Activate panel creation. If "left" the map will be displayed in
#' the left panel. Otherwise, if it is "right" the map will be displayed in the right panel.
#' By default NULL (No panel will be created).
#'
#' @return A `EarthEngineMap` object.
#' @examples
#' library(sf)
#' library(rgee)
#'
#' ee_Initialize()
#'
#' Map <- R6Map$new()
#'
#' nc <- st_read(system.file("shape/nc.shp", package = "sf")) %>%
#' st_transform(4326) %>%
#' sf_as_ee()
#'
#' ee_s2 <- ee$ImageCollection("COPERNICUS/S2")$
#' filterDate("2016-01-01", "2016-01-31")$
#' filterBounds(nc) %>%
#' ee_get(0:2)
#'
#' Map$centerObject(nc$geometry())
#' Map$addLayers(eeObject = ee_s2, legend = TRUE, position = "right")
#' Map$reset()
#'
#' # digging up the metadata
#' Map$previous_map_right$rgee$tokens
addLayers = function(eeObject,
visParams = NULL,
nmax = 5,
name = NULL,
shown = TRUE,
position = NULL,
opacity = 1,
legend = FALSE) {
# check packages
ee_check_packages("Map$addLayers", c("jsonlite", "leaflet"))
# is an ee.imagecollection.ImageCollection?
if (!any(class(eeObject) %in% "ee.imagecollection.ImageCollection")) {
stop("eeObject argument is not an ee$imagecollection$ImageCollection")
}
if (is.null(visParams)) {
visParams <- list()
}
# size of objects
eeObject_size <- eeObject %>%
ee$ImageCollection$size() %>%
ee$Number$getInfo()
m_img_list <- list()
if (is.null(name)) {
name <- tryCatch(
expr = eeObject %>%
ee$ImageCollection$aggregate_array("system:id") %>%
ee$List$getInfo() %>%
ee_utils_py_to_r() %>%
basename(),
error = function(e) sprintf("untitled_%02d", seq_len(eeObject_size))
)
if (length(name) == 0 | is.null(name)) name <- sprintf("untitled_%02d", seq_len(eeObject_size))
}
if (length(name) == 1) {
name <- sprintf("%s_%02d", name, seq_len(eeObject_size))
}
if (length(name) == length(eeObject_size)) {
stop("name does not have the same length than eeObject$size()$getInfo().")
}
m_img_list <- list()
for (index in seq_len(eeObject_size)) {
py_index <- index - 1
if (index == 1) {
m_img <- self$addLayer(
eeObject = ee_get(eeObject, index = py_index)$first(),
visParams = visParams,
name = name[index],
shown = shown,
opacity = opacity,
position = position,
legend = legend
)
} else {
m_img <- self$addLayer(
eeObject = ee_get(eeObject, index = py_index)$first(),
visParams = visParams,
name = name[index],
shown = shown,
opacity = opacity,
position = position,
legend = FALSE
)
}
m_img_list[[index]] <- m_img
}
if (isFALSE(self$save_maps)) {
Reduce('+', m_img_list)
}
}
),
private = list(
get_previous_map_right = function() {
self$previous_map_right
},
set_previous_map_right = function(val) {
self$previous_map_right <- val
},
get_previous_map_left = function() {
self$previous_map_left
},
set_previous_map_left = function(val) {
self$previous_map_left <- val
},
set_lat = function(val) {
self$lat <- val
},
set_lon = function(val) {
self$lon <- val
},
set_zoom = function(val) {
self$zoom <- val
},
get_center = function(eeObject, zoom, maxError) {
if (any(class(eeObject) %in% "ee.featurecollection.FeatureCollection")) {
message("NOTE: Center obtained from the first element.")
eeObject <- ee$Feature(ee$FeatureCollection$first(eeObject))
}
if (any(class(eeObject) %in% ee_get_spatial_objects("Nongeom"))) {
center <- tryCatch(
expr = eeObject$
geometry()$
centroid(maxError)$
getInfo() %>%
'[['('coordinates') %>%
ee_utils_py_to_r(),
error = function(e) {
message(
"The centroid coordinate was not possible",
" to estimate, assigning: c(0,0)"
)
c(0, 0)
}
)
if (is.null(center)) {
message(
"The centroid coordinate was not possible",
" to estimate, assigning: c(0,0)"
)
center <- c(0, 0)
}
} else if (any(class(eeObject) %in% "ee.geometry.Geometry")) {
center <- tryCatch(
expr = eeObject$
centroid(maxError)$
coordinates()$
getInfo() %>%
ee_utils_py_to_r(),
error = function(e) {
message(
"The centroid coordinate was not possible",
" to estimate, assigning: c(0,0)"
)
c(0, 0)
}
)
} else {
stop("Spatial Earth Engine Object not supported")
}
if (is.null(zoom)) {
zoom <- ee_getZoom(eeObject, maxError = maxError)
}
# Set new initial view
list(lon = center[1], lat = center[2], zoom = zoom)
},
ee_mapview = function() {
# check packages
private$ee_check_packages("ee_mapview", "leaflet")
m <- private$leaflet_default()
m$x$setView[[1]] <- c(self$lat, self$lon)
m$x$setView[[2]] <- if (is.null(self$zoom)) 1 else self$zoom
# EarthEngine Map parameters
# m$rgee$tokens <- NA
# m$rgee$name <- NA
# m$rgee$opacity <- NA
# m$rgee$shown <- NA
# m$rgee$position <- NA
# # legend parameters
# m$rgee$min <- NA
# m$rgee$max <- NA
# m$rgee$palette <- list(NA)
# m$rgee$legend <- NA
m
},
ee_addTile = function(tile, name, visParams, shown, opacity, position) {
# check packages
ee_check_packages("Map$addLayer", c("leaflet"))
m <- private$ee_mapview() %>%
leaflet::addTiles(
urlTemplate = tile,
layerId = name,
group = name,
options = leaflet::tileOptions(opacity = opacity)
) %>%
ee_mapViewLayersControl(names = name) %>%
leaflet::hideGroup(if (!shown) name else NULL)
# map parameters
m$rgee$tokens <- tile
m$rgee$name <- name
m$rgee$opacity <- opacity
m$rgee$shown <- shown
m$rgee$position <- position
# legend parameters
m$rgee$min <- if (is.null(visParams$min)) NA else visParams$min
m$rgee$max <- if (is.null(visParams$max)) NA else visParams$max
m$rgee$palette <- if (is.null(visParams$palette)) list(NA) else list(visParams$palette)
m$rgee$legend <- FALSE
m
},
save_map = function(map, position = NULL) {
if (is.null(position)) {
private$set_previous_map_right(self$previous_map_right + map)
} else {
if (tolower(position) == "right") {
private$set_previous_map_right(self$previous_map_right + map)
} else if (tolower(position) == "left") {
private$set_previous_map_left(self$previous_map_left + map)
} else {
stop("position should be a character either 'right' or 'left'")
}
}
},
leaflet_default = function(lon = -76.942478, lat = -12.172116, zoom = 18, default_maps = NULL) {
if (is.null(default_maps)) {
default_maps <- c(
"CartoDB.Positron", "OpenStreetMap",
"CartoDB.DarkMatter", "Esri.WorldImagery",
"OpenTopoMap"
)
}
m <- private$initBaseMaps(default_maps)
m <- leaflet::setView(map = m, lon, lat, zoom)
m <- leaflet::addLayersControl(
map = m,
baseGroups = default_maps,
position = "topleft"
)
m <- leaflet::addScaleBar(map = m, position = "bottomleft")
m <- leafem::addMouseCoordinates(m)
m <- leafem::addCopyExtent(m)
class(m) <- append(class(m),"EarthEngineMap")
m
},
initBaseMaps = function (map.types, canvas = FALSE, viewer.suppress = FALSE) {
lid <- seq_along(map.types)
m <- leaflet::leaflet(
height = NULL,
width = NULL,
options = leaflet::leafletOptions(
minZoom = 1, maxZoom = 52,
bounceAtZoomLimits = FALSE,
maxBounds = list(list(c(-90,-370)), list(c(90, 370))),
preferCanvas = canvas),
sizingPolicy = leaflet::leafletSizingPolicy(
viewer.suppress = viewer.suppress,
browser.external = viewer.suppress))
# add Tiles
m <- leaflet::addProviderTiles(
map = m,
provider = map.types[1],
layerId = map.types[1],
group = map.types[1],
options = leaflet::providerTileOptions(pane = "tilePane")
)
for (i in 2:length(map.types)) {
m <- leaflet::addProviderTiles(
map = m,
provider = map.types[i],
layerId = map.types[i],
group = map.types[i],
options = leaflet::providerTileOptions(pane = "tilePane"))
}
return(m)
},
upgrade_center_right = function(lon = 0, lat = 0, zoom = 10) {
self$previous_map_right <- self$previous_map_right %>%
leaflet::setView(lon, lat, zoom = zoom)
},
upgrade_center_left = function(lon = 0, lat = 0, zoom = 10) {
self$previous_map_left <- self$previous_map_left %>%
leaflet::setView(lon, lat, zoom = zoom)
},
ee_check_packages = function(fn_name, packages) {
pkg_exists <- rep(NA, length(packages))
counter <- 0
for(package in packages) {
counter <- counter + 1
pkg_exists[counter] <- requireNamespace(package, quietly = TRUE)
}
if (!all(pkg_exists)) {
to_install <- packages[!pkg_exists]
to_install_len <- length(to_install)
error_msg <- sprintf(
"%s required the %s: %s. Please install %s first.",
bold(fn_name),
if (to_install_len == 1) "package" else "packages",
paste0(bold(to_install), collapse = ", "),
if (to_install_len == 1) "it" else "them"
)
stop(error_msg)
}
}
)
)
#' R6 object (Map) to display Earth Engine (EE) spatial objects
#'
#' Create interactive visualizations of spatial EE objects
#' (ee$FeatureCollection, ee$ImageCollection, ee$Geometry, ee$Feature, and
#' ee$Image.) using \code{leaflet} in the backend.
#' @format An object of class environment with the
#' following functions:
#' \itemize{
#' \item \strong{addLayer(eeObject, visParams, name = NULL, shown = TRUE,
#' opacity = 1, legend = FALSE)}: Adds a given EE object to the map as a layer. \cr
#' \itemize{
#' \item \strong{eeObject:} The object to add to the interactive map.\cr
#' \item \strong{visParams:} List of parameters for visualization.
#' See details.\cr
#' \item \strong{name:} The name of the layer.\cr
#' \item \strong{shown:} A flag indicating whether the
#' layer should be on by default. \cr
#' \item \strong{opacity:} The layer's opacity represented as a number
#' between 0 and 1. Defaults to 1. \cr
#' \item \strong{legend:} Should a legend be plotted?. Ignore if \code{eeObject}
#' is not a single-band ee$Image.
#' }
#' \item \strong{addLayers(eeObject, visParams, name = NULL, shown = TRUE,
#' opacity = 1, legend = FALSE)}: Adds a given ee$ImageCollection to the map
#' as multiple layers. \cr
#' \itemize{
#' \item \strong{eeObject:} The ee$ImageCollection to add to the interactive map.\cr
#' \item \strong{visParams:} List of parameters for visualization.
#' See details.\cr
#' \item \strong{name:} The name of layers.\cr
#' \item \strong{shown:} A flag indicating whether
#' layers should be on by default. \cr
#' \item \strong{opacity:} The layer's opacity represented as a number
#' between 0 and 1. Defaults to 1. \cr
#' \item \strong{nmax:} Numeric. The maximum number of images to display.
#' By default 5. \cr
#' \item \strong{legend:} Should a legend be plotted?. Only the legend of
#' the first image is displayed.
#' }
#' \item \strong{setCenter(lon = 0, lat = 0, zoom = NULL)}: Centers the map
#' view at the given coordinates with the given zoom level. If no zoom level
#' is provided, it uses 1 by default.
#' \itemize{
#' \item \strong{lon:} The longitude of the center, in degrees.\cr
#' \item \strong{lat:} The latitude of the center, in degrees.\cr
#' \item \strong{zoom:} The zoom level, from 1 to 24.
#' }
#' \item \strong{setZoom(zoom = NULL)}: Sets the zoom level of the map.
#' \itemize{
#' \item \strong{zoom:} The zoom level, from 1 to 24.
#' }
#' \item \strong{centerObject(eeObject, zoom = NULL,
#' maxError = ee$ErrorMargin(1))}: Centers the
#' map view on a given object. If no zoom level is provided, it will
#' be predicted according to the bounds of the Earth Engine object specified.
#' \itemize{
#' \item \strong{eeObject:} EE object.\cr
#' \item \strong{zoom:} The zoom level, from 1 to 24.
#' \item \strong{maxError:} Max error when input
#' image must be reprojected to an explicitly
#' requested result projection or geodesic state.
#' }
#' }
#'
#' @details
#' `Map` use the Earth Engine method
#' \href{https://developers.google.com/earth-engine/api_docs#ee.data.getmapid/}{
#' getMapId} to fetch and return an ID dictionary being used to create
#' layers in a \code{leaflet} object. Users can specify visualization
#' parameters to Map$addLayer by using the visParams argument. Each Earth
#' Engine spatial object has a specific format. For
#' \code{ee$Image}, the
#' \href{https://developers.google.com/earth-engine/guides/image_visualization}{
#' parameters} available are:
#'
#' \tabular{lll}{
#' \strong{Parameter}\tab \strong{Description} \tab \strong{Type}\cr
#' \strong{bands} \tab Comma-delimited list of three band names to be
#' mapped to RGB \tab list \cr
#' \strong{min} \tab Value(s) to map to 0 \tab number or list of three
#' numbers, one for each band \cr
#' \strong{max} \tab Value(s) to map to 1 \tab number or list of three
#' numbers, one for each band \cr
#' \strong{gain} \tab Value(s) by which to multiply each pixel value \tab
#' number or list of three numbers, one for each band \cr
#' \strong{bias} \tab Value(s) to add to each Digital Number (DN)
#' value \tab number or list of three numbers, one for each band \cr
#' \strong{gamma} \tab Gamma correction factor(s) \tab number or list of
#' three numbers, one for each band \cr
#' \strong{palette} \tab List of CSS-style color strings
#' (single-band images only) \tab comma-separated list of hex strings \cr
#' \strong{opacity} \tab The opacity of the layer (0.0 is fully transparent
#' and 1.0 is fully opaque) \tab number \cr
#' }
#'
#' If you add an \code{ee$Image} to Map$addLayer without any additional
#' parameters, by default it assigns the first three bands to red,
#' green, and blue bands, respectively. The default stretch is based on the
#' min-max range. On the other hand, the available parameters for
#' \code{ee$Geometry}, \code{ee$Feature}, and \code{ee$FeatureCollection}
#' are:
#'
#' \itemize{
#' \item \strong{color}: A hex string in the format RRGGBB specifying the
#' color to use for drawing the features. By default #000000.
#' \item \strong{pointRadius}: The radius of the point markers. By default 3.
#' \item \strong{strokeWidth}: The width of lines and polygon borders. By
#' default 3.
#' }
#' @returns Object of class leaflet, with the following extra parameters: tokens, name,
#' opacity, shown, min, max, palette, and legend. Use the $ method to retrieve
#' the data (e.g. m$rgee$min).
#'
#' @examples
#' library(rgee)
#' library(sf)
#' ee_Initialize()
#'
#' # Case 1: Geometry*
#' geom1 <- ee$Geometry$Point(list(-73.53, -15.75))
#' Map$centerObject(geom1, zoom = 8)
#' m1 <- Map$addLayer(
#' eeObject = geom1,
#' visParams = list(
#' pointRadius = 10,
#' color = "FF0000"
#' ),
#' name = "Geometry-Arequipa"
#' )
#'
#' # Case 2: Feature
#' feature_arq <- ee$Feature(ee$Geometry$Point(list(-72.53, -15.75)))
#' m2 <- Map$addLayer(
#' eeObject = feature_arq,
#' name = "Feature-Arequipa"
#' )
#' m2 + m1
#'
#' # Case 4: Image
#' image <- ee$Image("LANDSAT/LC08/C01/T1/LC08_044034_20140318")
#' Map$centerObject(image)
#' m4 <- Map$addLayer(
#' eeObject = image,
#' visParams = list(
#' bands = c("B4", "B3", "B2"),
#' max = 10000
#' ),
#' name = "SF"
#' )
#'
#' # Case 5: ImageCollection
#' nc <- st_read(system.file("shape/nc.shp", package = "sf")) %>%
#' st_transform(4326) %>%
#' sf_as_ee()
#'
#' ee_s2 <- ee$ImageCollection("COPERNICUS/S2")$
#' filterDate("2016-01-01", "2016-01-31")$
#' filterBounds(nc) %>%
#' ee_get(0:4)
#' Map$centerObject(nc$geometry())
#' m5 <- Map$addLayers(ee_s2, legend = TRUE)
#' m5
#'
#' # Case 6: Map comparison
#' image <- ee$Image("LANDSAT/LC08/C01/T1/LC08_044034_20140318")
#' Map$centerObject(image)
#' m_ndvi <- Map$addLayer(
#' eeObject = image$normalizedDifference(list("B5", "B4")),
#' visParams = list(max = 0.7),
#' name = "SF_NDVI",
#' legend = TRUE
#' )
#' m6 <- m4 | m_ndvi
#' m6
#'
#' # Case 7: digging up the metadata
#' m6$rgee$tokens
#' m5$rgee$tokens
#' @export
Map <- R6Map$new(save_maps = FALSE)
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