MTA (version 0.6.0)

gdev: General Deviation

Description

Compute the deviation of each territorial unit as regards to all the study area (or a reference value).

Usage

gdev(x, var1, var2, type = "rel", ref)

Value

A vector is returned.

Arguments

x

a data.frame or a sf object including var1 and var2.

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).

ref

ratio of reference; if missing, the ratio of reference is the one of the whole study area (sum(var1) / sum(var2)).

Details

The relative global deviation is the ratio between var1/var2 and ref (100 * (var1 / var2) / ref). Values greater than 100 indicate that the unit ratio is greater than the ratio of reference. Values lower than 100 indicate that the unit ratio is lower than the ratio of reference.
The absolute global deviation is the amount of numerator that could be moved to obtain the ratio of reference on all units. ((var1 - (ref * var2)).

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)

if(require(mapsf)){
# compute absolute global deviation
com$gdevabs <- gdev(x = com, var1 = "INC", var2 = "TH", type = "abs")
# compute relative global deviation
com$gdevrel <- gdev(x = com, var1 = "INC", var2 = "TH", type = "rel")

# relative deviation map
# set breaks
bks <- c(min(com$gdevrel), 50, 75, 100, 125, 150, max(com$gdevrel))
# plot a choropleth map of the relative global deviation
mf_map(x = com, var = "gdevrel", 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 = "General Deviation (reference: Grand Paris Metropole)",
          credits = paste0("Sources: GEOFLA® 2015 v2.1, Apur, impots.gouv.fr",
                           "\nMTA", packageVersion("MTA")),
          arrow = FALSE)

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

mf_map(x = com, var = c("gdevabs", "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 = "General Deviation (reference: Grand Paris Metropole)",
          credits = paste0("Sources: GEOFLA® 2015 v2.1, Apur, impots.gouv.fr",
                           "\nMTA", packageVersion("MTA")),
          arrow = FALSE)
}