Moran plots in ggplot2

Moran plots are one of the many way to depict spatial autocorrelation:
moran.test(varofint,listw)
where “varofint” is the variable we are studying, “listw” a listwise neighbourhood matrix, and the function “moran.test” performs the Moran’s test (duh!) for spatial autocorrelation and is included in the spdep funtionality. The same plot can be done using ggplo2 library. Provided that we already have our listwise matrix of neighborhood relationships listw, we first define the variable and the lagged variable under study, computing their mean and saving them into a data frame (there are a lot of datasets you can find implemented in R: afcon, columbus, syracuse, just to cite a few). The purpose is to obtain something that looks like this (I have used my own *large* set of Spanish data to obtain it):

ggplot2.moranplot1

Upload your data. Here is Anselin (1995) data on African conflicts, afcon:

data(afcon)
varofint listw varlag var.name <- "Total Conflicts"
m.varofint m.varlag
and compute the local Moran's statistic using localmoran:

lisa
and save everything into a dataframe:
df

use these variables to derive the four sectors "High-High"(red), "Low-Low"(blue), "Low-High"(lightblue), "High-Low"(pink):
df$sector significance vec =df$m.varofint & df$varlag>=df$m.varlag]  df$sector[df$varofint<df$m.varofint & df$varlag<df$m.varlag]  df$sector[df$varofint<df$m.varofint & df$varlag>=df$m.varlag]  =df$m.varofint & df$varlag<df$m.varlag]

df$sec.data

df$sector.col[df$sec.data==1] <- "red"
df$sector.col[df$sec.data==2] <- "blue"
df$sector.col[df$sec.data==3] <- "lightblue"
df$sector.col[df$sec.data==4] <- "pink"
df$sector.col[df$sec.data==0] <- "white"

df$sizevar df$sizevar 0.1)
df$FILL df$BORDER
to get the ggplot graph:
p 0.05", "High-High", "Low-Low","Low-High","High-Low"))+
scale_x_continuous(name=var.name)+
scale_y_continuous(name=paste("Lagged",var.name))+
theme(axis.line=element_line(color="black"),
axis.title.x=element_text(size=20,face="bold",vjust=0.1),
axis.title.y=element_text(size=20,face="bold",vjust=0.1),
axis.text= element_text(colour="black", size=20, angle=0,face = "plain"),
plot.margin=unit(c(0,1.5,0.5,2),"lines"),
panel.background=element_rect(fill="white",colour="black"),
panel.grid=element_line(colour="grey"),
axis.text.x  = element_text(hjust=.5, vjust=.5),
axis.text.y  = element_text(hjust=1, vjust=1),
strip.text.x  = element_text(size = 20, colour ="black", angle = 0),
plot.title= element_text(size=20))+
stat_smooth(method="lm",se=F,colour="black", size=1)+
geom_vline(xintercept=m.varofint,colour="black",linetype="longdash")+
geom_hline(yintercept=m.varlag,colour="black",linetype="longdash")+
theme(legend.background =element_rect("white"))+
theme(legend.key=element_rect("white",colour="white"),
legend.text =element_text(size=20))

Check out the interactive shiny version on pracademic

A ggmap of 2015 Israeli elections by city

IL_el_percThe recent Israeli elections are a reminder of how Demography and Space play a crucial role in the outcome of the 20th Knesset. For more insight, read the full Demotrends blog post by Ashira Menashe-Oren the demographics of the Israeli electorate here. The map has been done using ggmap and ggplot, two simple mapping tools I really like. If you are interested in the code, below you can find the relative syntax and data.

To start upload the libraries:

library(maptools) #reads the shape file 
library(ggmap) 
library(ggplot2)

Download the shape file (I normally use Diva-GIS website) and read it:

map.ogr<- readOGR(".","ISR_adm1")

Data set:

df <- structure(list(lon = c(35.148529, 35.303546, 34.753934, 34.781768,34.989571, 34.824785, 34.808871, 34.883879, 34.844675, 34.90761, 35.010397, 34.871326, 35.21371, 34.655314, 34.887762, 34.792501, 34.574252, 34.791462, 34.748019, 34.787384, 34.853196, 34.811272, 34.919652, 34.888075, 35.098051, 35.119773, 34.872938, 34.835226, 34.988099, 35.002462), lat = c(32.517127, 32.699635, 31.394548, 32.0853, 32.794046, 32.068424, 32.072176, 32.149961, 32.162413, 32.178195, 31.890267, 32.184781, 31.768319, 31.804381, 32.084041, 31.973001, 31.668789, 31.252973, 32.013186, 32.015833, 32.321458, 31.892773, 32.434046, 31.951014, 33.008536, 32.809144, 31.931566,32.084932, 31.747041, 31.90912), City = structure(c(30L, 19L,24L, 29L, 9L, 25L, 7L, 11L, 10L, 14L, 16L, 23L, 13L, 1L, 21L,28L, 2L, 4L, 3L, 12L, 20L, 27L, 8L, 15L, 18L, 22L, 26L, 6L, 5L, 17L), .Label = c("Ashdod", "Ashkelon", "Bat yam", "Beersheva",  "Beit  Shemesh", "Bnei brak", "Giv'atayim", "Hadera", "Haifa",  "Herzliyya", "Hod HaSharon", "Holon", "Jerusalem", "Kefar Sava",  "Lod", "Modi'in - Makkabbim - Re'ut", "Modi'in Illit", "Nahariyya", "Nazareth ", "Netanya", "Petach Tikva", "Qiryat Atta", "Ra'annana",  "Rahat", "Ramat gan", "Ramla", "Rehovot", "Rishon", "Tel-Aviv",  "Umm Al-Fahm"), class = "factor"), most.votes = c(96.28, 91.41,  87.62, 34.03, 24.98, 30.93, 40.1, 38.77, 34.2, 34.66, 28.95,  32.75, 23.9, 30.96, 27.87, 29.78, 39.31, 37.17, 32.88, 30.86,  33.14, 26.95, 31.77, 32.22, 34.25, 35.01, 39.1, 57.56, 27.89,  71.63), party = structure(c(1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L,  2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 4L, 4L, 4L), .Label = c("joint list", "labour", "likud", "yahadut hatora"), class = "factor")), .Names = c("lon", "lat",  "City", "most.votes", "party"), class = "data.frame", row.names = c(NA,  -30L)) 

get the map using get_map

gmap <- get_map(location=c(34.2,29.4,36,33.5),zoom=7,source="stamen",maptype="watercolor")

and plot the map:


ggmap(gmap)+ 

geom_polygon(aes(x = long, y = lat, group=id), data = map.ogr, color ="blue", fill ="white", alpha = .8, size = .4)+ 

geom_point(aes(x=lon,y=lat,color=party,size=most.votes),data=df)+ scale_colour_discrete("Coalition", labels = c("Joint List", 
"Labour","Likud","United Torah Judaism"), breaks = c("joint list", 
"labour","likud","yahadut hatora")) +  
scale_size_continuous("Coalition", labels = c("Joint List",
 "Labour","Likud","United Torah Judaism"), breaks = c("joint list", 
"labour","likud","yahadut hatora"), range=c(10,15), guide = FALSE)+ 
theme(axis.text=element_text(size=18), 
plot.title=element_text(size=rel(3)), 
legend.key = element_rect(fill = "white"), 
legend.background =element_rect("white"), 
legend.text = element_text(size = 25), 
legend.title = element_text(size = 25))+ 
guides(colour = guide_legend(override.aes = list(size=8)))+  
labs(x="",y="")

IL_el_perc_city_names_color If you want to add city names you can use the “annotate” option, adding the code below after guides(...)+. I have modified the coordinates to avoid overlapping of labels and colored names to match the color of the winner party.

annotate("text", x=c(35.14853+ 0.2,35.21371+0.15,35.00246+ 0.15,34.79146+0.15, 34.98957-0.08,34.78177-0.14), 
y=c(32.51713,31.76832,31.90912,31.25297, 32.79405,32.08530),
size=5,font=3, 
label=c("Umm Al-Fahm","Jerusalem","Modin  Illit",
"Beersheva","Haifa","Tel Aviv"), 
color=c("darkred","blue4","deeppink4", "blue4",
"springgreen4","green4"))+

For beginners I highly recommend ggplot2 mailing list, a great and shame-free place to learn.