Drawing maps

1.1 rworldmap, World Map and countries

library(rworldmap) # start with the entire world newmap <- getMap(resolution = "low") plot(newmap, main = "World") # crop to the area desired (outside US) # (can use maps.google.com, right-click, drop lat/lon markers at corners) plot(newmap , xlim = c(-139.3, -58.8) # if you reverse these, the world gets flipped , ylim = c(13.5, 55.7) , asp = 1 # different aspect projections , main = "US from worldmap" )

1.2 ggmap, World Map and countries

library(ggplot2) map.world <- map_data(map = "world") # map = name of map provided by the maps package. # These include county, france, italy, nz, state, usa, world, world2. str(map.world) # how many regions length(unique(map.world$region)) # how many group polygons (some regions have multiple parts) length(unique(map.world$group)) p1 <- ggplot(map.world, aes(x = long, y = lat, group = group)) p1 <- p1 + geom_polygon() # fill areas p1 <- p1 + labs(title = "World, plain") #print(p1) p2 <- ggplot(map.world, aes(x = long, y = lat, group = group, colour = region)) p2 <- p2 + geom_polygon() # fill areas p2 <- p2 + theme(legend.position="none") # remove legend with fill colours p2 <- p2 + labs(title = "World, colour borders") #print(p2) p3 <- ggplot(map.world, aes(x = long, y = lat, group = group, fill = region)) p3 <- p3 + geom_polygon() # fill areas p3 <- p3 + theme(legend.position="none") # remove legend with fill colours p3 <- p3 + labs(title = "World, filled regions") #print(p3) p4 <- ggplot(map.world, aes(x = long, y = lat, group = group, colour = region)) p4 <- p4 + geom_path() # country outline, instead p4 <- p4 + theme(legend.position="none") # remove legend with fill colours p4 <- p4 + labs(title = "World, path outlines only") #print(p4) library(gridExtra) grid.arrange(p1, p2, p3, p4, ncol=2, main="ggmap examples")

1.3 ggmap, New Mexico and Albuquerque

library(ggmap) library(mapproj) map <- get_map( location = "New Mexico" # google search string , zoom = 7 # larger is closer , maptype = "hybrid" # map type ) p <- ggmap(map) p <- p + labs(title = "NM hybrid") print(p) # some options are cute, but not very informative map <- get_map( location = "Albuquerque, New Mexico" # google search string , zoom = 10 # larger is closer , maptype = "watercolor" # map type ) p <- ggmap(map) p <- p + labs(title = "Albuquerque watercolor") print(p)

1.2 Adding data to map underlay

1.2.1 Points

# identify some points around campus dat <- read.table(text = " location lat long MathStat 35.08396 -106.62410 Ducks 35.08507 -106.62238 SC1Class 35.08614 -106.62349 Biology 35.08243 -106.62296 CSEL 35.08317 -106.62414 ", header = TRUE) ## Sometimes the watercolor style can look nice. # get map layer map <- get_map( location = "University of New Mexico" # google search string , zoom = 16 # larger is closer , maptype = "watercolor" # map type ) # plot map p <- ggmap(map) p <- p + geom_point(data = dat, aes(x = long, y = lat, shape = location, colour = location), size = 7) p <- p + geom_text(data = dat, aes(x = long, y = lat, label = location), hjust = -0.2) # legend positioning, removing grid and axis labeling p <- p + theme( legend.position = "none" # remove legend , panel.grid.major = element_blank() , panel.grid.minor = element_blank() , axis.text = element_blank() , axis.title = element_blank() , axis.ticks = element_blank() ) p <- p + labs(title = "UNM SC1 locations") print(p) # Let s say I started in my office in Math & Stat, # then visited with the Ducks, # then taught the SC1 class, # then walked over to Biology, # then finished by picking up a book in the CSEL library. ## Satellite view with points plotted from get_googlemap() # the points need to be called "x" and "y" to get the google markers and path dat.pts <- data.frame(x = dat$long, y = dat$lat) # get map layer map <- get_googlemap( "University of New Mexico" # google search string , zoom = 16 # larger is closer , maptype = "satellite" # map type , markers = dat.pts # markers for map , path = dat.pts # path, in order of points , scale = 2 ) # plot map p <- ggmap(map , extent = "device" # remove white border around map , darken = 0.2 # darken map layer to help points stand out ) p <- p + geom_text(data = dat, aes(x = long, y = lat, label = location), hjust = -0.2, colour = "white", size = 6) # legend positioning, removing grid and axis labeling p <- p + theme( legend.position = c(0.05, 0.05) # put the legend inside the plot area , legend.justification = c(0, 0) , legend.background = element_rect(colour = F, fill = "white") , legend.key = element_rect(fill = F, colour = F) , panel.grid.major = element_blank() , panel.grid.minor = element_blank() , axis.text = element_blank() , axis.title = element_blank() , axis.ticks = element_blank() ) p <- p + labs(title = "UNM Walk around campus") print(p)

1.3 Incidence and density maps

str(crime) # Extract location of crimes in houston violent_crimes <- subset(crime, ((offense != "auto theft") & (offense != "theft") & (offense != "burglary"))) # rank violent crimes violent_crimes$offense <- factor(violent_crimes$offense , levels = c("robbery", "aggravated assault" , "rape", "murder")) # restrict to downtown violent_crimes <- subset(violent_crimes, ((-95.39681 <= lon) & (lon <= -95.34188) & (29.73631 <= lat) & (lat <= 29.784))) map <- get_map( location = "Houston TX" , zoom = 14 , maptype = "roadmap" , color = "bw" # make black & white so color is data ) p <- ggmap(map) p <- p + geom_point(data = violent_crimes , aes(x = lon, y = lat, size = offense, colour = offense)) # legend positioning, removing grid and axis labeling p <- p + theme( legend.position = c(0.0, 0.7) # put the legend inside the plot area , legend.justification = c(0, 0) , legend.background = element_rect(colour = F, fill = "white") , legend.key = element_rect(fill = F, colour = F) , panel.grid.major = element_blank() , panel.grid.minor = element_blank() , axis.text = element_blank() , axis.title = element_blank() , axis.ticks = element_blank() ) print(p) # 2D density plot p <- ggmap(map) overlay <- stat_density2d(data = violent_crimes , aes(x = lon, y = lat, fill = ..level.. , alpha = ..level..) , size = 2, bins = 4, geom = "polygon") p <- p + overlay p <- p + scale_fill_gradient("ViolentnnCrimennDensity") p <- p + scale_alpha(range = c(0.4, 0.75), guide = FALSE) p <- p + guides(fill = guide_colorbar(barwidth = 1.5, barheight = 10)) #p <- p + inset(grob = ggplotGrob(ggplot() + overlay + theme_inset()) # , xmin = -95.35836, xmax = Inf, ymin = -Inf, ymax = 29.75062) print(p) p <- p + facet_wrap( ~ day, nrow = 2) print(p)

1.4 Minard’s map, modern

library(ggplot2) library(plyr) troops <- read.table("http://stat405.had.co.nz/data/minard-troops.txt", header=T) cities <- read.table("http://stat405.had.co.nz/data/minard-cities.txt", header=T) russia <- map_data("world", region = "USSR") p <- ggplot(troops, aes(long, lat)) p <- p + geom_polygon(data = russia, aes(x = long, y = lat, group = group), fill = "white") p <- p + geom_path(aes(size = survivors, colour = direction, group = group), lineend = "round") p <- p + geom_text(data = cities, aes(label = city), size = 3) p <- p + scale_size(range = c(1, 6) , breaks = c(1, 2, 3) * 10^5 , labels = c(1, 2, 3) * 10^5) p <- p + scale_colour_manual(values = c("bisque2", "grey10")) p <- p + xlab(NULL) p <- p + ylab(NULL) p <- p + coord_equal(xlim = c(20, 40), ylim = c(50, 60)) print(p)

1.5 Choropleth maps

library(maps) library(ggplot2) library(plyr) # make fake choropleth data newmexico <- map("county", regions = "new mexico", plot = FALSE, fill = TRUE) newmexico <- fortify(newmexico) newmexico <- ddply(newmexico, "subregion", function(df){ mutate(df, fake = rnorm(1)) } # make standard ggplot map (without geom_map) p <- ggplot(newmexico, aes(x = long, y = lat, group = group, fill = fake)) p <- p + geom_polygon(colour = "white", size = 0.3) print(p) # Now, a fancier map using ggmap... library(ggmap) p <- qmap( New Mexico , zoom = 7, maptype = satellite , legend = topleft ) p <- p + geom_polygon(data = newmexico , aes(x = long, y = lat, group = group, fill = fake) , color = white , alpha = .75, size = .2) # Add some city names, by looking up their location cities <- c("Albuquerque NM", "Las Cruces NM", "Rio Rancho NM", "Santa Fe NM", "Roswell NM", "Farmington NM", "South Valley NM", "Clovis NM", "Hobbs NM", "Alamogordo NM", "Carlsbad NM", "Gallup NM", "Los Alamos NM") cities_locs <- geocode(cities) cities_locs$city <- cities p <- p + geom_text(data = cities_locs, aes(label = city) , color = yellow , size = 3) print(p)
Reference:

http://statacumen.com/teach/SC1/SC1_16_Maps.pdf

http://spatialanalysis.co.uk/2012/02/great-maps-ggplot2/

http://spatialanalysis.co.uk/2012/01/coming-age-spatial-data-visualisation/

http://geoacrobats.blogspot.de/2011/12/overview-map-with-ggplot2.html

http://www.thisisthegreenroom.com/2009/choropleths-in-r/

http://nrelscience.org/2013/05/30/this-is-how-i-did-it-mapping-in-r-with-ggplot2/

https://uchicagoconsulting.wordpress.com/tag/r-ggplot2-maps-visualization/

http://blog.revolutionanalytics.com/2009/10/geographic-maps-in-r.html

http://www.molecularecologist.com/2012/09/making-maps-with-r/

http://maojf.blogspot.de/2012/01/guides-on-generating-map-plot-with-r.html

Data source

http://www.gadm.org/country

http://www.fas.harvard.edu/~chgis/data/dcw/

http://openstreetmapdata.com/data

UI Elements

tabsetPanel Create a tabset that contains tabPanel elements. Tabsets are useful for dividing output into multiple independently viewable sections.

tabPanel Create a tab panel that can be included within a tabsetPanel.

conditionalPanel Creates a panel that is visible or not, depending on the value of a JavaScript expression. The JS expression is evaluated once at startup and whenever Shiny detects a relevant change in input/output.

headerPanel Create a header panel containing an application title.

mainPanel Create a main panel containing output elements that can in turn be passed to pageWithSidebar.

sidebarPanel Create a sidebar panel containing input controls that can in turn be passed to pageWithSidebar.

wellPanel Creates a panel with a slightly inset border and grey background. Equivalent to Twitter Bootstrap’s well CSS class.

Input Elements

actionButton Creates an action button whose value is initially zero, and increments by one each time it is pressed.

checkboxGroupInput Create a group of checkboxes that can be used to toggle multiple choices independently. The server will receive the input as a character vector of the selected values.

checkboxInput Create a checkbox that can be used to specify logical values.

dateInput Creates a text input which, when clicked on, brings up a calendar that the user can click on to select dates.

dateRangeInput Creates a pair of text inputs which, when clicked on, bring up calendars that the user can click on to select dates

fileInput Create a ﬁle upload control that can be used to upload one or more ﬁles. Does not work on older browsers, including Internet Explorer 9 and earlier

numericInput Create an input control for entry of numeric values

radioButtons Create a set of radio buttons used to select an item from a list.

selectInput Create a select list that can be used to choose a single or multiple items from a list of values.

sliderInput Constructs a slider widget to select a numeric value from a range.

submitButton Create a submit button

textInput Create an input control for entry of unstructured text values

Output Elements

htmlOutput Render a reactive output variable as HTML within an application page. The text will be included within an HTML div tag, and is presumed to contain HTML content which should not be escaped.

imageOutput Render a renderImage within an application page.

plotOutput Render a renderPlot within an application page

tableOutput Render a renderTable within an application page.

textOutput Create an input control for entry of unstructured text values

verbatimTextOutput Render a reactive output variable as verbatim text within an application page. The text will be included within an HTML pre tag.

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