MTA (version 0.1.2)

tdev: Territorial Deviation

Description

This function computes the deviation between regional ratios and ratios of an aggregated level. Each elementary unit's value will be compared to the value of the aggregated level it belongs to.

Usage

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

Arguments

x

a data frame.

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.

Value

A vector is returned.

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

# NOT RUN {
# load data
data("GrandParisMetropole")
# compute absolute territorial deviation (EPT level)
com$tdevabs <- tdev(x = com, var1 = "INC", var2 = "TH", type = "abs", 
                              key = "EPT")
# compute relative territorial deviation (EPT level)
com$tdevrel <- tdev(x = com, var1 = "INC", var2 = "TH", type = "rel", 
                              key = "EPT")

# map deviations
if(require('cartography')){
  library(sp)
  # set graphical parameters
  par(mar = c(0,0,1.2,0))
  # set breaks
  bks <- c(min(com$tdevrel),75,100,125,150,max(com$tdevrel))
  # set colot palette
  cols <- carto.pal(pal1 = "blue.pal", n1 = 2,
                    pal2 = "wine.pal", n2 = 3)
  # plot a choropleth map of the relative territorial deviation
  choroLayer(spdf = com.spdf, df = com, var = "tdevrel",
             legend.pos = "topleft",
             breaks = bks, border = NA,
             col = cols)
  # add symbols proportional to the absolute territorial deviation
  com$sign <- ifelse(test = com$tdevabs<0, yes = "negative", no = "positive")
  propSymbolsTypoLayer(spdf = com.spdf, df = com, var = "tdevabs",var2 = "sign",
                       legend.var.pos = "left",legend.values.rnd = -2, 
                       legend.var2.values.order = c("positive", "negative"),
                       legend.var.title.txt = "Absolute Deviation",
                       col = c("#ff000050","#0000ff50"),legend.var2.pos = "n",
                       legend.var.style = "e", inches = 0.2)
  # add EPT boundaries
  plot(ept.spdf, add=TRUE)
  # add a layout
  layoutLayer(title = "Territorial Deviation",
              sources = "GEOFLA<U+00AE> 2015 v2.1, Apur, impots.gouv.fr", 
              author = "MTA")
}
# }