choroplethr: state_choropleth – R documentation

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state_choropleth

Create a choropleth of US States

Description

The map used is state.map in the package choroplethrMaps. See state.regions in the choroplethrMaps package for a data.frame that can help you coerce your regions into the required format.

Usage

state_choropleth(
  df,
  title = "",
  legend = "",
  num_colors = 7,
  zoom = NULL,
  reference_map = FALSE
)

Arguments

`df`	A data.frame with a column named "region" and a column named "value". Elements in the "region" column must exactly match how regions are named in the "region" column in state.map.
`title`	An optional title for the map.
`legend`	An optional name for the legend.
`num_colors`	The number of colors to use on the map. A value of 0 uses a divergent scale (useful for visualizing negative and positive numbers), A value of 1 uses a continuous scale (useful for visualizing outliers), and a value in [2, 9] will use that many quantiles.
`zoom`	An optional vector of states to zoom in on. Elements of this vector must exactly match the names of states as they appear in the "region" column of ?state.regions.
`reference_map`	If true, render the choropleth over a reference map from Google Maps.

Examples

## Not run: 
# default parameters
data(df_pop_state)
state_choropleth(df_pop_state, 
                 title  = "US 2012 State Population Estimates", 
                 legend = "Population")

# choropleth over reference map of continental usa
data(continental_us_states)
state_choropleth(df_pop_state, 
                 title         = "US 2012 State Population Estimates",
                 legend        = "Population",
                 zoom          = continental_us_states, 
                 reference_map = TRUE)

# continuous scale and zoom
data(df_pop_state)
state_choropleth(df_pop_state, 
                 title      = "US 2012 State Population Estimates", 
                 legend     = "Population", 
                 num_colors = 1,
                 zoom       = c("california", "oregon", "washington"))

# demonstrate user creating their own discretization of the input
# demonstrate how choroplethr handles character and factor values
data(df_pop_state)
df_pop_state$str = ""
for (i in 1:nrow(df_pop_state))
{
  if (df_pop_state[i,"value"] < 1000000)
  {
    df_pop_state[i,"str"] = "< 1M"
  } else {
    df_pop_state[i,"str"] = "> 1M"
  }
}
df_pop_state$value = df_pop_state$str
state_choropleth(df_pop_state, title = "Which states have less than 1M people?")


## End(Not run)

choroplethr

Simplify the Creation of Choropleth Maps in R

v3.7.0

BSD_3_clause + file LICENSE

Authors

Ari Lamstein [aut, cre], Brian Johnson [ctb], Trulia, Inc. [cph]

Initial release