Leaflet Assignment

library(leaflet)
library(tidyverse)

## Loading tidyverse: ggplot2
## Loading tidyverse: tibble
## Loading tidyverse: tidyr
## Loading tidyverse: readr
## Loading tidyverse: purrr
## Loading tidyverse: dplyr

## Warning: package 'tibble' was built under R version 3.4.4

## Warning: package 'purrr' was built under R version 3.4.4

## Warning: package 'dplyr' was built under R version 3.4.4

## Conflicts with tidy packages ----------------------------------------------

## filter(): dplyr, stats
## lag():    dplyr, stats

library(tidycensus)
library(leaflet)
library(stringr)
library(sf)

## Linking to GEOS 3.6.1, GDAL 2.2.0, proj.4 4.9.3

v15 <- load_variables(2016, "acs5", cache = TRUE)

View(v15)

#census_api_key("b24ce41117d6a656e716897a0b2bb1d5efec1fa6")

#census_api_key("install = TRUE")

Instructions: To complete this assignment, work the following problems and publish your completed work on RPubs.

Problem 1

Select a leaflet provider and a color palette to construct a choropleth of median income by census tract in a US county of your choice.

mi_med <- get_acs(geography = "tract",
                  variables = "B06011_001", 
                  state = "MI",
                  county = "Kent County",  
                  geometry = TRUE) 

## Downloading feature geometry from the Census website.  To cache shapefiles for use in future sessions, set `options(tigris_use_cache = TRUE)`.

## Warning: package 'bindrcpp' was built under R version 3.4.4

pal <- colorNumeric(palette = "YlGnBu", 
                    domain = mi_med$estimate)

mi_med %>%
    st_transform(crs = "+init=epsg:4326") %>%
    leaflet(width = "100%") %>%
    addProviderTiles(provider = "Esri.WorldImagery") %>%
    addPolygons(popup = ~ str_extract(NAME, "^([^,]*)"),
                stroke = FALSE,
                smoothFactor = 0,
                fillOpacity = 0.7,
                color = ~ pal(estimate)) %>%
    addLegend("bottomright", 
              pal = pal, 
              values = ~ estimate,
              title = "Median Income",
              labFormat = labelFormat(prefix = "$"),
              opacity = 1)

Problem 2

Reproduce your choropleth with the same color palette but a different provider.

mi_med %>%
    st_transform(crs = "+init=epsg:4326") %>%
    leaflet(width = "100%") %>%
    addProviderTiles(provider = "Thunderforest.SpinalMap") %>%
    addPolygons(popup = ~ str_extract(NAME, "^([^,]*)"),
                stroke = FALSE,
                smoothFactor = 0,
                fillOpacity = 0.7,
                color = ~ pal(estimate)) %>%
    addLegend("bottomright", 
              pal = pal, 
              values = ~ estimate,
              title = "Median Income",
              labFormat = labelFormat(prefix = "$"),
              opacity = 1)

Problem 3

Again: Reproduce your choropleth with the same color palette but a different provider.

mi_med %>%
    st_transform(crs = "+init=epsg:4326") %>%
    leaflet(width = "100%") %>%
    addProviderTiles(provider = "NASAGIBS.ViirsEarthAtNight2012") %>%
    addPolygons(popup = ~ str_extract(NAME, "^([^,]*)"),
                stroke = FALSE,
                smoothFactor = 0,
                fillOpacity = 0.7,
                color = ~ pal(estimate)) %>%
    addLegend("bottomright", 
              pal = pal, 
              values = ~ estimate,
              title = "Median Income",
              labFormat = labelFormat(prefix = "$"),
              opacity = 1)

Problem 4

Select one provider from the three that you’ve tried. Try a different color palette from a different source.

pal2 <- colorNumeric(palette = "viridis", 
                    domain = mi_med$estimate)

mi_med %>%
    st_transform(crs = "+init=epsg:4326") %>%
    leaflet(width = "100%") %>%
    addProviderTiles(provider = "Thunderforest.SpinalMap") %>%
    addPolygons(popup = ~ str_extract(NAME, "^([^,]*)"),
                stroke = FALSE,
                smoothFactor = 0,
                fillOpacity = 0.9,
                color = ~ pal2(estimate)) %>%
    addLegend("bottomright", 
              pal = pal2, 
              values = ~ estimate,
              title = "Median Income",
              labFormat = labelFormat(prefix = "$"),
              opacity = 1)

Problem 5

Again, stick with the current provider, but try a color palette from a third source.

pal3 <- colorNumeric(palette = "Greens", 
                    domain = mi_med$estimate)

mi_med %>%
    st_transform(crs = "+init=epsg:4326") %>%
    leaflet(width = "100%") %>%
    addProviderTiles(provider = "Thunderforest.SpinalMap") %>%
    addPolygons(popup = ~ str_extract(NAME, "^([^,]*)"),
                stroke = FALSE,
                smoothFactor = 0,
                fillOpacity = 0.9,
                color = ~ pal3(estimate)) %>%
    addLegend("bottomright", 
              pal = pal3, 
              values = ~ estimate,
              title = "Median Income",
              labFormat = labelFormat(prefix = "$"),
              opacity = 1)

Problem 6

From the providers and color palettes, which you have tried, which one do you prefer?

I prefer the Thunderforest.SpinalMap provider because its so unique.

I like the Viridis palette because it is actually legible with the reds/oranges of the SpinalMap

No code is required.