A quick introduction

The ggiraph package let R users to make ggplot interactive. The package is an htmlwidget. Below an example:

It extends ggplot2 with new geom functions:

• geom_bar_interactive
• geom_boxplot_interactive
• geom_line_interactive
• geom_map_interactive
• geom_path_interactive
• geom_point_interactive
• geom_polygon_interactive
• geom_rect_interactive
• geom_segment_interactive
• geom_text_interactive
• geom_tile_interactive

These understand three aesthetics to let you add interactivity:

• tooltip: column of dataset that contains tooltips to be displayed when mouse is over elements.
• onclick: column of dataset that contains javascript function to be executed when elements are clicked.
• data_id: column of dataset that contains id to be associated with elements. This aesthetic is mandatory when you want to use an hover effect or when you want to enable selection of points in shiny applications.

Let’s prepare a ggplot object with mpg dataset.

library(ggiraph)

head(mpg)

## # A tibble: 6 × 11
##   manufacturer model displ  year   cyl      trans   drv   cty   hwy    fl
##          <chr> <chr> <dbl> <int> <int>      <chr> <chr> <int> <int> <chr>
## 1         audi    a4   1.8  1999     4   auto(l5)     f    18    29     p
## 2         audi    a4   1.8  1999     4 manual(m5)     f    21    29     p
## 3         audi    a4   2.0  2008     4 manual(m6)     f    20    31     p
## 4         audi    a4   2.0  2008     4   auto(av)     f    21    30     p
## 5         audi    a4   2.8  1999     6   auto(l5)     f    16    26     p
## 6         audi    a4   2.8  1999     6 manual(m5)     f    18    26     p
## # ... with 1 more variables: class <chr>

g <- ggplot(mpg, aes( x = displ, y = cty, color = hwy) ) + theme_minimal()

my_gg <- g + geom_point_interactive(aes(tooltip = model), size = 2) 
ggiraph(code = print(my_gg), width = .7)

my_gg <- g + geom_point_interactive(
    aes(tooltip = model, data_id = model), size = 2) 
ggiraph(code = print(my_gg), width = .7, hover_css = "cursor:pointer;fill:red;stroke:red;")

crimes <- data.frame(state = tolower(rownames(USArrests)), USArrests)
head(crimes)

##                 state Murder Assault UrbanPop Rape
## Alabama       alabama   13.2     236       58 21.2
## Alaska         alaska   10.0     263       48 44.5
## Arizona       arizona    8.1     294       80 31.0
## Arkansas     arkansas    8.8     190       50 19.5
## California california    9.0     276       91 40.6
## Colorado     colorado    7.9     204       78 38.7

# create an 'onclick' column
crimes$onclick <- sprintf("window.open(\"%s%s\")",
  "http://en.wikipedia.org/wiki/", as.character(crimes$state) )

gg_crime <- ggplot(crimes, aes(x = Murder, y = Assault, color = UrbanPop )) + 
  geom_point_interactive(
    aes( data_id = state, tooltip = state, onclick = onclick ), size = 3 ) + 
  scale_colour_gradient(low = "#999999", high = "#FF3333") + 
  theme_minimal()

ggiraph(code = print(gg_crime),
        hover_css = "fill-opacity:.3;cursor:pointer;")