|
| 1 | +--- |
| 2 | +name: Choropleth Maps |
| 3 | +permalink: r/choropleth-maps/ |
| 4 | +description: How to make a choropleth map in R. A choropleth map shades geographic regions by value. |
| 5 | +layout: base |
| 6 | +thumbnail: thumbnail/choropleth.jpg |
| 7 | +language: r |
| 8 | +page_type: example_index |
| 9 | +display_as: maps |
| 10 | +order: 0 |
| 11 | +output: |
| 12 | + html_document: |
| 13 | + keep_md: true |
| 14 | +--- |
| 15 | + |
| 16 | +```{r, echo = FALSE, message=FALSE} |
| 17 | +knitr::opts_chunk$set(message = FALSE, warning=FALSE) |
| 18 | +``` |
| 19 | +### New to Plotly? |
| 20 | + |
| 21 | +Plotly's R library is free and open source!<br> |
| 22 | +[Get started](https://plot.ly/r/getting-started/) by downloading the client and [reading the primer](https://plot.ly/r/getting-started/).<br> |
| 23 | +You can set up Plotly to work in [online](https://plot.ly/r/getting-started/#hosting-graphs-in-your-online-plotly-account) or [offline](https://plot.ly/r/offline/) mode.<br> |
| 24 | +We also have a quick-reference [cheatsheet](https://images.plot.ly/plotly-documentation/images/r_cheat_sheet.pdf) (new!) to help you get started! |
| 25 | + |
| 26 | +### Version Check |
| 27 | + |
| 28 | +Version 4 of Plotly's R package is now [available](https://plot.ly/r/getting-started/#installation)!<br> |
| 29 | +Check out [this post](http://moderndata.plot.ly/upgrading-to-plotly-4-0-and-above/) for more information on breaking changes and new features available in this version. |
| 30 | +```{r} |
| 31 | +library(plotly) |
| 32 | +packageVersion('plotly') |
| 33 | +``` |
| 34 | + |
| 35 | +# Choropleth Maps in R |
| 36 | +```{r} |
| 37 | +library(plotly) |
| 38 | +df <- read.csv("https://raw.githubusercontent.com/plotly/datasets/master/2011_us_ag_exports.csv") |
| 39 | +df$hover <- with(df, paste(state, '<br>', "Beef", beef, "Dairy", dairy, "<br>", |
| 40 | + "Fruits", total.fruits, "Veggies", total.veggies, |
| 41 | + "<br>", "Wheat", wheat, "Corn", corn)) |
| 42 | +# give state boundaries a white border |
| 43 | +l <- list(color = toRGB("white"), width = 2) |
| 44 | +# specify some map projection/options |
| 45 | +g <- list( |
| 46 | + scope = 'usa', |
| 47 | + projection = list(type = 'albers usa'), |
| 48 | + showlakes = TRUE, |
| 49 | + lakecolor = toRGB('white') |
| 50 | +) |
| 51 | +
|
| 52 | +p <- plot_geo(df, locationmode = 'USA-states') %>% |
| 53 | + add_trace( |
| 54 | + z = ~total.exports, text = ~hover, locations = ~code, |
| 55 | + color = ~total.exports, colors = 'Purples' |
| 56 | + ) %>% |
| 57 | + colorbar(title = "Millions USD") %>% |
| 58 | + layout( |
| 59 | + title = '2011 US Agriculture Exports by State<br>(Hover for breakdown)', |
| 60 | + geo = g |
| 61 | + ) |
| 62 | +
|
| 63 | +p |
| 64 | +``` |
| 65 | + |
| 66 | + |
| 67 | +### World Choropleth Map |
| 68 | + |
| 69 | +```{r} |
| 70 | +df <- read.csv('https://raw.githubusercontent.com/plotly/datasets/master/2014_world_gdp_with_codes.csv') |
| 71 | +
|
| 72 | +# light grey boundaries |
| 73 | +l <- list(color = toRGB("grey"), width = 0.5) |
| 74 | +
|
| 75 | +# specify map projection/options |
| 76 | +g <- list( |
| 77 | + showframe = FALSE, |
| 78 | + showcoastlines = FALSE, |
| 79 | + projection = list(type = 'Mercator') |
| 80 | +) |
| 81 | +
|
| 82 | +p <- plot_geo(df) %>% |
| 83 | + add_trace( |
| 84 | + z = ~GDP..BILLIONS., color = ~GDP..BILLIONS., colors = 'Blues', |
| 85 | + text = ~COUNTRY, locations = ~CODE, marker = list(line = l) |
| 86 | + ) %>% |
| 87 | + colorbar(title = 'GDP Billions US$', tickprefix = '$') %>% |
| 88 | + layout( |
| 89 | + title = '2014 Global GDP<br>Source:<a href="https://www.cia.gov/library/publications/the-world-factbook/fields/2195.html">CIA World Factbook</a>', |
| 90 | + geo = g |
| 91 | + ) |
| 92 | +
|
| 93 | +p |
| 94 | +``` |
| 95 | + |
| 96 | +### Choropleth Inset Map |
| 97 | + |
| 98 | +```{r} |
| 99 | +df <- read.csv('https://raw.githubusercontent.com/plotly/datasets/master/2014_ebola.csv') |
| 100 | +# restrict from June to September |
| 101 | +df <- subset(df, Month %in% 6:9) |
| 102 | +# ordered factor variable with month abbreviations |
| 103 | +df$abbrev <- ordered(month.abb[df$Month], levels = month.abb[6:9]) |
| 104 | +# September totals |
| 105 | +df9 <- subset(df, Month == 9) |
| 106 | +
|
| 107 | +# common plot options |
| 108 | +g <- list( |
| 109 | + scope = 'africa', |
| 110 | + showframe = F, |
| 111 | + showland = T, |
| 112 | + landcolor = toRGB("grey90") |
| 113 | +) |
| 114 | +
|
| 115 | +g1 <- c( |
| 116 | + g, |
| 117 | + resolution = 50, |
| 118 | + showcoastlines = T, |
| 119 | + countrycolor = toRGB("white"), |
| 120 | + coastlinecolor = toRGB("white"), |
| 121 | + projection = list(type = 'Mercator'), |
| 122 | + list(lonaxis = list(range = c(-15, -5))), |
| 123 | + list(lataxis = list(range = c(0, 12))), |
| 124 | + list(domain = list(x = c(0, 1), y = c(0, 1))) |
| 125 | +) |
| 126 | +
|
| 127 | +g2 <- c( |
| 128 | + g, |
| 129 | + showcountries = F, |
| 130 | + bgcolor = toRGB("white", alpha = 0), |
| 131 | + list(domain = list(x = c(0, .6), y = c(0, .6))) |
| 132 | +) |
| 133 | +
|
| 134 | +p <- df %>% |
| 135 | + plot_geo( |
| 136 | + locationmode = 'country names', sizes = c(1, 600), color = I("black") |
| 137 | + ) %>% |
| 138 | + add_markers( |
| 139 | + y = ~Lat, x = ~Lon, locations = ~Country, |
| 140 | + size = ~Value, color = ~abbrev, text = ~paste(Value, "cases") |
| 141 | + ) %>% |
| 142 | + add_text( |
| 143 | + x = 21.0936, y = 7.1881, text = 'Africa', showlegend = F, geo = "geo2" |
| 144 | + ) %>% |
| 145 | + add_trace( |
| 146 | + data = df9, z = ~Month, locations = ~Country, |
| 147 | + showscale = F, geo = "geo2" |
| 148 | + ) %>% |
| 149 | + layout( |
| 150 | + title = 'Ebola cases reported by month in West Africa 2014<br> Source: <a href="https://data.hdx.rwlabs.org/dataset/rowca-ebola-cases">HDX</a>', |
| 151 | + geo = g1, geo2 = g2 |
| 152 | + ) |
| 153 | +
|
| 154 | +p |
| 155 | +``` |
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