R_map_session_1_Final_code.txt

#--------------------------------------------------------------------------------------
#--------------------------------------------------------------------------------------
#--------------------R for georaphic map Session 1-------------------------------------
#--------------------------------------------------------------------------------------
#--------------------------------------------------------------------------------------

# Package loading
# Chargement des packages

library(rgdal) 
library(mapproj)
library(maptools)
library(maps)
library(ggplot2)
library(ggrepel)
library(dplyr)
library(legendMap)
library(scales)


# English: Set the working directory
# French: Configurer le repertoire de travail

setwd("C:/Users/ANGE/Documents/R MAP")


# English: Clear objects from the R environment workspace
# French: Eliminer tout fichiers dans l'espace de travail R

rm(list=ls())


# English: Set the shapefile full path
# French: Indiquer le chemin d'acces au shapefile


mySHP="C:/Users/ANGE/Documents/R MAP"


# English: Import the shapefile
# French: Importer le shapefile

myFile=readOGR (mySHP, layer="SEN_adm1", stringsAsFactors=FALSE)

# English: Check the class of the shapefile
# French: Verifier la class de l'objet shapefile

class(myFile)


# English: Check the variables names
# French: Verifier le nom des variables de l'objet shapefile

names(myFile)

# English: Check the regions names
# French: Vérifier le nom des regions

print(myFile$NAME_1)



# English: Change the object sp file into dataframe format for ggplot2
# French: Passer du format polygone spatial a celui de tableau pour usage avec ggplot2

myDF = fortify(myFile, region = "NAME_1")


# English: Overview of the data myDF
# French: Apercu du tableau myDF

head(myDF, 4)

# English: Change long to Longitude and lat to Latitude respectively
# French: Changer long et lat en Longitude et latitude respectivement

myDF = rename(myDF, Longitude = long, Latitude= lat)

# English: Overview of the data myDF
# French: Apercu du tableau myDF

head(myDF, 4)


# English: Make a basic plot
# French: Faire une carte basique

p <- ggplot() +
  geom_polygon(data = myDF, 
               aes(x = Longitude, y = Latitude, group = group), 
               color = "black", size = 0.25) +
  coord_map() +
  theme_minimal() +
  ggtitle("Basic map with ggplot2")

p

#------------------------------------------------------------------
#------------------------------------------------------------------

# English: Rendering a choropleth map
# French: Faire une carte choroplethe


# English:Import the data we want to plot on the map.
# Here that is the production of pearl millet per region

# French: Importer les donnees que nous voulons projeter sur la carte
# Ici, nous utiliserons les données de production de mil suivant les regions

mydata = read.csv("production_data.csv", header=TRUE, sep=";")


# English: Import the the regions names for annotation step
# French: Importer le nom des regions pour annotation de la carte


mydata1 = read.csv("region_names.csv", header=TRUE, sep=";")



# English: Overview of the data mydata
# French: Apercu du jeu de donnees mydata

head(mydata, 4)

# English: Overview of the data mydata1
# French: Apercu du jeu de donnees mydata1

head(mydata1, 4)


# English: Join your data to the shapefile
# French: Joindre vos donnees au shapefile


plotData <- left_join(myDF, mydata)


# English: Overview of the data plotData
# French: Apercu du jeu de donnees plotData

head(plotData)


# English: Make the plot
# French: Faire la carte


p <- ggplot() +
  
  
  # English: Plot the shapefile geographic information
  # French: Projeter les contours geographiques du shapefile
  
  geom_polygon(data = plotData, 
               aes(x = Longitude, 
                   y = Latitude, 
                   group = group,
                   fill = Production), 
               color = "black", 
               size = 0.25) +
  #-------------------------------------------------------------------
  
  # English: Map projection type. Default is "mercator". 
  #See help(coord_map() for other choice)
  
  # French: Type de projection. Mercator par defaut
  # Voir help(coord_map() pour d'autres choix)
  coord_map() +
  
  
  #------------------------------------------------------------------
  
  
  # English: Color choice, direction = 1 means colored from lowest to highest value
  # French: Choix de couleur. direction=1 veut dire colorer par ordre croissant de valeur
  scale_fill_distiller(palette = "Greens", direction=1) +
  
  #------------------------------------------------------------------


  # English: Plot the localization points corresponding to each region
  # French: Projeter les points geographiques de chaque region
  
  geom_point(
    data=mydata1, 
    aes(x=long, y=lat), 
    shape = 21,
    fill = "white",
    size = 3, 
    color = "black") +
  
  #---------------------------------------------------------------------
  
  # English: Avoid overlapping text for the points annotation
  # French: Eviter la superposition des noms de regions
  geom_label_repel(data=mydata1, 
                   aes(x=long, y=lat, label=Region),
                   fontface = 'bold', color = 'black',
                   box.padding = 0.35, point.padding = 0.5,
                   segment.color = 'grey10')+
  
  
  # English: Scale bar and north arrow
  # French: Ajouter le north geographique et l'echelle
  
  scale_bar(lon = -12, lat = 16, #--longitude and latitude of the scale bar position 
            
            distance_lon = 40, distance_lat = 10, #--legnth and width of each rectangle
            
            distance_legend = 25, #--distance between legend rectangles and legend texts
            
            dist_unit = "km", #-- Unit
            
            arrow_length = 10, #-- Arrow length
            
            arrow_distance = 50, #-- Arrow distance to the scale bar
            
            arrow_north_size = 6) + #-- Arrow size
  
  
  # English: Theme option
  # French: Mise forme de l'arriere plan
  
  theme_minimal() + # Simple background
  
  
  theme(panel.grid.major = 
          element_line(
            colour = "black", 
            size = 0.5, 
            linetype = "dotted")) + # Customize the grid line type, size and color
  
  theme(plot.background = 
          element_rect(
            colour = "white", 
            size = 1)) + # Customize the background line type, color and size
  
  # Add a title
  ggtitle("Map of Pearl Millet Production in Senegal (Rainy season 2017)")
  
  p
  
#----------------------------END-------------------------------------------------------