MTA (version 0.6.0)

tdev: Territorial Deviation

Description

Compute the deviation of each territorial unit as regards to an intermediate territorial level of reference.

Usage

tdev(x, var1, var2, type = "rel", key)

Value

A vector is returned.

Arguments

x

a dataframe or a sf object including var1 and var2 and an aggregation key field (territorial belonging).

var1

name of the numerator variable in x.

var2

name of the denominator variable in x.

type

type of deviation; "rel" for relative deviation, "abs" for absolute deviation (see Details).

key

aggregation key field for measuring the deviation (intermediate territorial level).

Details

The relative territorial deviation is the ratio between var1/var2 and var1/var2 at the aggregated level. Values greater than 100 indicate that the unit ratio is greater than the ratio at the aggregated level. Values lower than 100 indicate that the unit ratio is lower than the ratio of the aggregated level.
The absolute territorial deviation is the amount of numerator that could be moved to obtain the ratio of the aggregated level on all belonging units.

Examples

# Load data
library(sf)
com <- st_read(system.file("metroparis.gpkg", package = "MTA"), layer = "com", quiet = TRUE)
ept <- st_read(system.file("metroparis.gpkg", package = "MTA"), layer = "ept", quiet = TRUE)

# compute absolute territorial deviation
com$tdevabs <- tdev(x = com, var1 = "INC", var2 = "TH", key = "EPT", 
                    type = "abs")
# compute relative territorial deviation
com$tdevrel <- tdev(x = com, var1 = "INC", var2 = "TH", key = "EPT", 
                    type = "rel")
if(require(mapsf)){
# relative deviation map
# set breaks
bks <- c(min(com$tdevrel), 80, 91, 100, 110, 125, max(com$tdevrel))
# plot a choropleth map of the relative territorial deviation
mf_map(x = com, var = "tdevrel", type = "choro", leg_pos = "topleft",
       leg_title = "Relative Deviation\n(100 = general average)",
       breaks = bks, border = NA,
       pal = c("#4575B4", "#91BFDB", "#E0F3F8", "#FEE090", "#FC8D59", "#D73027"))

# add EPT boundaries
mf_map(x = ept, col = NA, add = TRUE)

# layout
mf_layout(title = "Territorial Deviation (reference: EPT of belonging)",
         credits = paste0("Sources: GEOFLA® 2015 v2.1, Apur, impots.gouv.fr",
                          "\nMTA", packageVersion("MTA")),
         arrow = FALSE)


# absolute deviation map
com$sign <- ifelse(test = com$tdevabs < 0, yes = "Under-Income", no = "Over-Income")
mf_map(ept)

mf_map(x = com, var = c("tdevabs", "sign"), type = "prop_typo", inches = 0.2,
      leg_title = c("Absolute Deviation\n(Income redistribution, euros)",
                    "Redistribution direction"), 
      leg_pos = c("topleft", "topright"), leg_val_rnd = -2,
      val_order = c("Under-Income", "Over-Income"),
      pal =  c("#ff0000","#0000ff"), add = TRUE)

# layout
mf_layout(title = "Territorial Deviation (reference: EPT of belonging)",
         credits = paste0("Sources: GEOFLA® 2015 v2.1, Apur, impots.gouv.fr",
                          "\nMTA", packageVersion("MTA")),
         arrow = FALSE)
}