flowtype {cartograflow}R Documentation

Compute bilateral several flow types

Description

Compute bilateral flow type: volumn (gross), balance (net), asymetry, min/max ... from an initial asymetric matrix

Usage

flowtype(
  tab,
  origin = NULL,
  destination = NULL,
  fij = NULL,
  format,
  lowup,
  net,
  x
)

Arguments

tab

is the input flow dataset

origin

the place of origin code

destination

the place of destination code

fij

the flow value between origin and destination places

format

specify the flow dataset format, "M " for square matrix [n*n] or L for long [i,j,data]

lowup

for extracting the lower or upper triangular sub-portion of the bilateral volum matrix. See Details.

net

for extracting the "positive" or the "negative" flow values of the bilateral balance) matrix

x

enter the flow indicator type : "alltypes", "flux", "transpose", "bivolum", "bibal","biasym","bimin", "bimax","birange" and "bidisym"

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 :
Param x: - x = "flux" for the initial flow: (Fij)
- x = "transpose" for the reverse flow value: (Fji) =t(Fij)
- x = "bivolum" for the bilateral volum or gross flow: FSij=(Fij+Fji)
- x = "bibal" for the bilateral balance or net flow: FBij=(Fij-Fji)
- x = "biasym" for asymetry of bilateral flow: FAij=(FBij/FSij)
- x = "bimin" for the minimum of bilateral flow: minFij=(Fij, Fji)
- x = "bimax" for the maximum of bilateral flow: Fij(Fij, Fji)
- x = "birange" for the amplitude of bilateral flows: rangeFij=(maxFij - minFij)
- x = "bidisym" for the bilateral disymetry: FDij=(rangeFij/FSij) - x = "alltypes" for computing all the available types of flows
Param lowup is for reducing the matrix:
- lowup ="up" for triangular part above the main diagonal
- lowup = "low" for triangular part below the main diagonal
Param net is for extracting positive or negative flow values of the bilateral balance (bibal matrix):
- net ="negative" values
- net ="positive" values

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: Matrix 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 = "bibal")

## 1b:Computes flowtypes: Long format
types_all <- flowtype(flows,origin ="i",destination="j",fij="Fij", format = "L",
x = "alltypes")
bivol<- flowtype(flows,origin ="i",destination="j",fij="Fij",format = "L",
x = "bivolum",lowup="up")
bibal_net<- flowtype(flows,origin ="i",destination="j",fij="Fij",format = "L",
x = "bibal", net="negative")

# 2:flowmapping: example of bibal_net
flowmap(bibal_net,
  format = "L", bkg, code = "EPT_NUM",
  filter = TRUE, threshold = 20, taille = 5, a.head = 1,
)


[Package cartograflow version 1.0.3 Index]