cartogrammes.R

# load libraries
library(sf)
library(cartography)
library(cartogram)

## Import
# get the path to the shapefile embedded in sf package
shapepath <- system.file("shape/nc.shp", 
                         package="sf")
# import the shapefile
nc <- sf::st_read(shapepath)
# change the projection of the map
nc <- sf::st_transform(nc, 3857)
# get a figure ratio adapted to the basemap
figdim <- getFigDim(x = nc, width = 800, mar = c(0,0,1.2,0), res = 100)


# data preparation
# compute the sudden infant deaths per 1000 births
nc$share <- 100000 * nc$SID74 / nc$BIR74
# quantization breaks of the rate
bks <- getBreaks(v = nc$share, method = "quantile", nclass = 5)
# correct the breaks to use the global rate as limit of class 
global_rate <- sum(nc$SID74) * 100000 / sum(nc$BIR74)
bks[4] <- global_rate
# get a color palette
cols <- carto.pal(pal1 = "green.pal", n1 = 3, pal2 = "wine.pal", n2 = 2)


## Choropleth layer
png(filename = "map1.png", width = figdim[1], height = figdim[2],
    res = 100)
# set figure margins and background color
par(mar = c(0,0,1.2,0), bg = "lemonchiffon")
# display the sudden infant deaths per 1000 births
choroLayer(x = nc,var = "share", breaks = bks, col = cols,
           border = "khaki", lwd = 0.5, 
           legend.title.txt = "Sudden infant death syndrome rate*", 
           legend.pos = 'topleft', legend.values.rnd = 0)

# add a title and layout
layoutLayer(title = "Sudden Infant Death Syndrome in North Carolina, 1974-1978", 
            sources = "", north = TRUE, scale = 50,tabtitle = TRUE,
            theme = "sand.pal", frame = FALSE,  
            author = "*per 100,000 live births. Source: North Carolina SIDS data set")
dev.off()


## Choropleth layer
png(filename = "map2.png", width = figdim[1], height = figdim[2],
    res = 100)
## Proportional and Choropleth Symbols Layer
# set figure margins
par(mar = c(0,0,1.2,0), bg = "lemonchiffon")
# display the North Carolina counties
plot(st_geometry(nc), col = "khaki4", border = "khaki3")
# display circles
propSymbolsChoroLayer(x = nc,var = "BIR74", inches = 0.35,
                      var2 = "share", breaks = bks, col = cols, 
                      legend.var.title.txt = "N. of live births", 
                      legend.var.pos = 'bottomleft', 
                      legend.var2.values.rnd = 0,
                      legend.var2.pos = "topleft", 
                      legend.var2.title.txt = "Sudden infant death syndrome rate*")
# add a title and layout
layoutLayer(title = "Sudden Infant Death Syndrome in North Carolina, 1974-1978", 
            sources = "", north = TRUE, scale = 50,tabtitle = TRUE,
            theme = "sand.pal", frame = FALSE, 
            author = "*per 100,000 live births. Source: North Carolina SIDS data set")
dev.off()



# Continuous cartogram 
nc_cont <- cartogram_cont(nc, "BIR74")

## Choropleth layer
png(filename = "map3.png", width = figdim[1], height = figdim[2],
    res = 100)
# set figure margins and background color
par(mar = c(0,0,1.2,0), bg = "lemonchiffon")
# display the sudden infant deaths per 1000 births
choroLayer(x = nc_cont, var = "share", breaks = bks, col = cols,
           border = "khaki", lwd = 0.5, 
           legend.title.txt = "Sudden infant death syndrome rate*", 
           legend.pos = 'topleft', legend.values.rnd = 0)

text(x=-9405313, y=4082976, labels = "Counties sizes are proportional to the number\nof live births between 1974 and 1978", 
     adj = 0, cex = 0.8)
# add a title and layout
layoutLayer(title = "Sudden Infant Death Syndrome in North Carolina, 1974-1978", 
            sources = "", north = FALSE, scale = NULL,tabtitle = TRUE,
            theme = "sand.pal", frame = FALSE,  
            author = "*per 100,000 live births. Source: North Carolina SIDS data set")
dev.off()


nc_ncont <- cartogram_ncont(nc, "BIR74")

## Choropleth layer
png(filename = "map4.png", width = figdim[1], height = figdim[2],
    res = 100)
# set figure margins and background color
par(mar = c(0,0,1.2,0), bg = "lemonchiffon")
# display the sudden infant deaths per 1000 births
choroLayer(x = nc_ncont, var = "share", breaks = bks, col = cols,
           border = "khaki", lwd = 0.5, 
           legend.title.txt = "Sudden infant death syndrome rate*", 
           legend.pos = 'topleft', legend.values.rnd = 0)
plot(st_geometry(nc), col=NA, lwd = 0.5, border = "khaki", add=T)
text(x=-9382321, y=4082976, 
     labels = "Counties sizes are proportional to the number\nof live births between 1974 and 1978", 
     adj = 0, cex = 0.8)
# add a title and layout
layoutLayer(title = "Sudden Infant Death Syndrome in North Carolina, 1974-1978", 
            sources = "", north = FALSE, scale = NULL,tabtitle = TRUE,
            theme = "sand.pal", frame = FALSE,  
            author = "*per 100,000 live births. Source: North Carolina SIDS data set")
dev.off()



nc_dorling <- cartogram_dorling(nc, "BIR74", k = 5)
## Choropleth layer
png(filename = "map5.png", width = figdim[1], height = figdim[2],
    res = 100)
# set figure margins and background color
par(mar = c(0,0,1.2,0), bg = "lemonchiffon")
# display the sudden infant deaths per 1000 births
choroLayer(x = nc_dorling, var = "share", breaks = bks, col = cols,
           border = "khaki", lwd = 0.5, 
           legend.title.txt = "Sudden infant death syndrome rate*", 
           legend.pos = 'topleft', legend.values.rnd = 0)
# plot(st_geometry(nc), col=NA, lwd = 0.5, border = "khaki", add=T)
text(x=-9602842, y=4060000, 
     labels = "Circles sizes are proportional to the number\nof live births between 1974 and 1978", 
     adj = 0, cex = 0.8)
# add a title and layout
layoutLayer(title = "Sudden Infant Death Syndrome in North Carolina, 1974-1978", 
            sources = "", north = FALSE, scale = NULL,tabtitle = TRUE,
            theme = "sand.pal", frame = FALSE,  
            author = "*per 100,000 live births. Source: North Carolina SIDS data set")
dev.off()

w <- 1-( nc$BIR74 / max(nc$BIR74))  
nc_dorling <- cartogram_dorling(nc, "BIR74", 
                                k = 5, m_weight = w)
## Choropleth layer
png(filename = "map6.png", width = figdim[1], height = figdim[2],
    res = 100)
# set figure margins and background color
par(mar = c(0,0,1.2,0), bg = "lemonchiffon")
# display the sudden infant deaths per 1000 births
choroLayer(x = nc_dorling, var = "share", breaks = bks, col = cols,
           border = "khaki", lwd = 0.5, 
           legend.title.txt = "Sudden infant death syndrome rate*", 
           legend.pos = 'topleft', legend.values.rnd = 0)
# plot(st_geometry(nc), col=NA, lwd = 0.5, border = "khaki", add=T)
text(x=-9602842, y=4060000, 
     labels = "Circles sizes are proportional to the number\nof live births between 1974 and 1978", 
     adj = 0, cex = 0.8)
# add a title and layout
layoutLayer(title = "Sudden Infant Death Syndrome in North Carolina, 1974-1978", 
            sources = "", north = FALSE, scale = NULL,
            tabtitle = TRUE,
            theme = "sand.pal", frame = FALSE,  
            author = "*per 100,000 live births. Source: North Carolina SIDS data set")
dev.off()


sessionInfo()
# R version 3.5.1 (2018-07-02)
# Platform: x86_64-pc-linux-gnu (64-bit)
# Running under: Debian GNU/Linux 9 (stretch)
# 
# Matrix products: default
# BLAS: /usr/lib/libblas/libblas.so.3.7.0
# LAPACK: /usr/lib/lapack/liblapack.so.3.7.0
# 
# locale:
#   [1] LC_CTYPE=fr_FR.UTF-8       LC_NUMERIC=C               LC_TIME=fr_FR.UTF-8       
# [4] LC_COLLATE=fr_FR.UTF-8     LC_MONETARY=fr_FR.UTF-8    LC_MESSAGES=fr_FR.UTF-8   
# [7] LC_PAPER=fr_FR.UTF-8       LC_NAME=C                  LC_ADDRESS=C              
# [10] LC_TELEPHONE=C             LC_MEASUREMENT=fr_FR.UTF-8 LC_IDENTIFICATION=C       
# 
# attached base packages:
#   [1] stats     graphics  grDevices utils     datasets  methods   base     
# 
# other attached packages:
#   [1] cartogram_0.1.0   cartography_2.1.1 sf_0.6-3         
# 
# loaded via a namespace (and not attached):
#   [1] Rcpp_0.12.17      lattice_0.20-35   class_7.3-14      grid_3.5.1        spData_0.2.9.0   
# [6] DBI_1.0.0         magrittr_1.5      e1071_1.6-8       units_0.6-0       sp_1.3-1         
# [11] packcircles_0.3.2 rgdal_1.3-3       tools_3.5.1       yaml_2.1.19       compiler_3.5.1   
# [16] classInt_0.2-3    rgeos_0.3-28