flowtype: Compute flowdata types (volum, balance)

In fbahoken/cartogRaflow: Filtering Matrix for Flow Mapping

Description

Compute gross (volumn) and net (balance) flows from initial asymetric flow values

Usage

flowtype(tab, format, x)

Arguments

tab	is the input flow dataset
format	specify the flow dataset format, "M " for square matrix [n*n] or L for long [i,j,data]
x	enter the computation type : "flux", "transpose", "bivolum" and "bisold".

Details

The matrice must be squared (if not, see flowcarre). This function compute for all pairs or origin-destination places (i,j) involved in an asymetric flow matrix (Fij<> Fji) several matrix :
- x = "flux" for remaining initial flow (Fij)
- x = "transpose" for reverse flow value (Fji)
- x = "bivolum" for bilateral gross flow Vij=(Fij+Fji)
- x = "bisold" for bilateral net flow Sij=(Fij-Fji)

References

Bahoken Francoise, 2016, L'approche cartographique de la décomposition des matrices de flux, Mappemonde, Revue sur l'image géographique et les formes du territoire, number 116, URL : https://mappemonde-archive.mgm.fr/num44/articles/art14404.html

Examples

library(cartograflow)
data(flowdata)
bkg <- system.file("shape/MGP_TER.shp",
  package = "cartograflow",
  lib.loc = NULL, mustWork = TRUE
)

## 1a:Computes flowtypes: Matrice format
matflow <- flowtabmat(flows, matlist = "M")
m <- flowtype(matflow, format = "M", x = "flux")
m <- flowtype(matflow, format = "M", x = "transpose")
m <- flowtype(matflow, format = "M", x = "bivolum")
m <- flowtype(matflow, format = "M", x = "bisold")

## 1b:Computes flowtypes: Long format
list <- flowtabmat(matflow, matlist = "L")
colnames(list) <- c("i", "j", "Fij")
l_all <- flowtype(list, format = "L", x = "all")
l_sold <- flowtype(list, format = "L", x = "bisold")

# 2:flowmapping: example of bisold
flowmap(l_sold,
  format = "L", bkg, code = "EPT_NUM",
  filter = TRUE, threshold = 20, taille = 5
)

fbahoken/cartogRaflow documentation built on Oct. 15, 2021, 11:09 a.m.