btb_ptsToGrid: Compute a grid from centroid points

In btb: Beyond the Border - Kernel Density Estimation for Urban Geography

Compute a grid from centroid points

Description

Function to compute a grid (regular or not) from centroid points.

(Fonction permettant de générer une grille (régulière ou non) à partir de centroïdes)

Usage

btb_ptsToGrid(
  pts,
  sEPSG = NA,
  iCellSize = NULL,
  names_centro = c("x_centro", "y_centro"),
  inspire = F
)

Arguments

pts	A simple data.frame with the centroids coordinates of the squares to draw, or a sf object of centroides. To generate an irregular grid, a column with each cell size must be provided and named iCellSize. (Un simple data.frame comportant les coordonnées des carrés à dessiner, ou un objet sf des centroides. Pour obtenir une grille irrégulière, il faut fournir une colonne indiquant la taille de chaque carreau, et nommée iCellSize.
sEPSG	EPSG code of projection (character). For example, the RGF93 / Lambert-93 projection has "2154" code. (code EPSG de la projection (character). Par exemple, la projection RGF93 / Lambert-93 a pour code "2154".)
iCellSize	Cell size of the grid. If this argument is provided, the grid is regular. (Taille des carreaux de la grille. Si cet argument est fourni, la grille est régulière.)
names_centro	(character vector) vector of names for longitude/latitude variables. Default c("x_centro","y_centro"). vecteur des noms des variables de longitude/latitude. Par défaut : c("x_centro","y_centro")
inspire	(boolean) : if TRUE, returns a column for Inspire grid names.

Value

Returns an object of class sf and data.frame.

(Retourne un objet de classe sf et data.frame.)

Examples

 
# example 1 - regular grid
pts <- data.frame(x_centro = c(100, 100, 300, 300, 500), 
y_centro = c(100, 300, 100, 300, 100))
carResult <- btb_ptsToGrid(pts = pts, sEPSG = "2154", iCellSize = 200)
# write_sf(obj = carResult, dsn = "regularGrid.shp", delete_layer = TRUE)

# example 2 - irregular grid
pts <- data.frame(x = c(50, 50, 150, 150, 300)
                 , y = c(50, 150, 50, 150, 100)
                 , iCellSize = c(50, 50, 50, 50, 100))
carResult <- btb_ptsToGrid(pts = pts, sEPSG = "2154",names_centro=c("x","y"))
# write_sf(obj = carResult, dsn = "irregularGrid.shp", delete_layer = TRUE)
# Exemple 3 : sf points (no epsg)
pts <- data.frame(x = c(100, 100, 300, 300, 500), y = c(100, 300, 100, 300, 100))
pts <- sf::st_as_sf(pts,coords=c("x","y"))
carResult <- btb_ptsToGrid(pts = pts, sEPSG = "2154", iCellSize = 200)
# Exemple 3 : sf points (no epsg)
pts <- data.frame(x = c(100, 100, 300, 300, 500), 
y = c(100, 300, 100, 300, 100))
pts <- sf::st_as_sf(pts,coords=c("x","y"),crs=2154)
carResult <- btb_ptsToGrid(pts = pts, sEPSG = "2154", iCellSize = 200)

btb documentation built on Oct. 24, 2022, 5:10 p.m.