ttt_flowmapper: Flowmapper

In tributetotobler/ttt: Tribute to Tobler

Flowmapper

Description

Build flowmaps

Usage

ttt_flowmapper(
  x,
  xid = "id",
  df,
  dfid = c("i", "j"),
  dfvar = "fij",
  size = "thickness",
  type = "arrows",
  decreasing = FALSE,
  add = FALSE,
  lwd = 1,
  col = "#FF000099",
  border = "#4a0c25",
  k = NULL,
  df2 = NULL,
  df2id = "id",
  df2var,
  k2 = NULL,
  col2 = "white",
  border2 = "black",
  lwd2 = 2,
  plot = TRUE
)

Arguments

x	an sf object (polygon or multipolygons).
xid	name of the identifier variable in x, default is "id".
df	name of the numeric field in df to plot flows.
dfid	name of the two identifier variables in df, default is c("i","j").
dfvar	name of the numeric variable to plot flows, default is "fij".
size	way of calculating the size of the flows, "thickness" ou "area, default is "thickness".
type	type of flows, "rect" (for rectangles) or "arrows" (for arrows), default is "arrows".
decreasing	display order, default is FALSE.
add	whether to add the layer to an existing plot (TRUE) or not (FALSE), default is TRUE
lwd	flows borders width, default is 1.
col	color of flows, default is "#00FF0090"
border	color of flows borders, default is "#4a0c25"
k	value to increase or decrease the size of the flows (in units of the map), default is NULL. To be improved...
df2	dataframe containg data to plot proportional circles between flows, default is NULL.
df2id	name of the numeric field in df2, default is "id"
df2var	name of the numeric variable to plot circles.
k2	value to increase or decrease the size of the circles (in units of the map), default is NULL. To be improved...
col2	color of circles, default is "white"
border2	color of circles borders, default is "black".
lwd2	circle borders width, default is 2.
plot	display or not the map, default = TRUE

Examples

library(sf)

# Import
crs <- "+proj=robin +lon_0=0 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs"

subregions <- st_read(system.file("subregions.gpkg", package="flowmapper")) %>% st_transform(crs)
migr <- read.csv(system.file("migrantstocks2019.csv", package="flowmapper"))

#  Selection, filtrage, traitement en amont

threshold <- 1500
migr <- migr[migr$fij >= threshold,]

# Example 1

c <- ttt_flowmapper(
 x = subregions,
 xid = "id",
 df = migr,
 dfid = c("i","j"),
 dfvar = "fij"
)

# Example 2

intra <- migr[migr$i == migr$j,c("i","fij")]
colnames(intra) <- c("id","nb")

plot(st_geometry(subregions), col = "#CCCCCC", border = "white", lwd = 0.5)
c <- ttt_flowmapper(
 x = subregions,
 xid = "id",
 df = migr,
 dfid = c("i","j"),
 dfvar = "fij",
 size = "thickness",
 type = "rect",
 decreasing = FALSE,
 add = TRUE,
 lwd = 1,
 col = "#00FF0090",
 border = "#4a0c25",
 k = NULL,
 df2 = intra,
 df2id = "id",
 df2var = "nb"
)

# Example 3

crs <- "+proj=aeqd +lat_0=90 +lon_0=50 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs "
subregions2 <- st_transform(subregions, crs)

plot(st_geometry(subregions2), col = "#CCCCCC", border = "white", lwd = 0.5)
c <- ttt_flowmapper(
 x = subregions2,
 xid = "id",
 df = migr,
 dfid = c("i","j"),
 dfvar = "fij",
 add = TRUE
)

# Example 4

crs <- "+proj=ortho +lat_0=42.5333333333 +lon_0=-72.53333333339999 +x_0=0 +y_0=0 +a=6370997 +b=6370997 +units=m +no_defs"
flows <- smoothr::densify(c[[3]], n = 30) %>% st_transform(crs)
plot(st_geometry(subregions) %>% st_transform(crs), col ="#CCCCCC", border = "white")
plot(st_geometry(flows), col ="#FF000099", add = TRUE)
plot(st_centroid(st_geometry(c[[2]])) %>% st_transform(crs), add = TRUE, pch = 20, cex = 1.3, col ="black")

tributetotobler/ttt documentation built on Sept. 15, 2022, 5:41 p.m.